Long chain branched (lcb), block, or interconnected copolymers of ethylene in combination with one other polymer

ABSTRACT

An ethylenic polymer comprising amyl groups from about 0.1 to about 2.0 units per 1000 carbon atoms as determined by Nuclear Magnetic Resonance and both a peak melting temperature, T m , in ° C., and a heat of fusion, H f , in J/g, as determined by DSC Crystallinity, where the numerical values of T m  and H f  correspond to the relationship T m ≧(0.2143*H f )+79.643. An ethylenic polymer comprising at least one preparative TREF fraction that elutes at 95° C. or greater using a Preparative Temperature Rising Elution Fractionation method, where at least one preparative TREF fraction that elutes at 95° C. or greater has a gpcBR value greater than 0.05 and less than 5 as determined by gpcBR Branching Index by 3D-GPC, and where at least 5% of the ethylenic polymer elutes at a temperature of 95° C. or greater based upon the total weight of the ethylenic polymer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority benefit under 35 USC §119(e) toU.S. Provisional Patent Application No. 61/036,329, filed Mar. 13, 2008,the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

There are many types of polyethylene made and sold today. Two types inparticular are made by various suppliers and sold in large quantities.These two types are linear low density polyethylene (LLDPE) and highpressure free radical polyethylene (usually called LDPE). Sometimespolymer users blend these two types of polyethylene together to try tomodify properties such as flowability or processability. However, thisblending can also bring deficiencies in other physical properties. Thus,it would be advantageous to have similar mechanical properties to LLDPEand also the processability similar to that of LDPE.

We have now discovered new polymers which have the performanceattributes of both LLDPE and LDPE.

SUMMARY OF THE INVENTION

In one embodiment, an ethylenic polymer is claimed comprising at least0.1 amyl branches per 1000 carbon atoms as determined by NuclearMagnetic Resonance and both a highest peak melting temperature, T_(m),in ° C., and a heat of fusion, H_(f), in J/g, as determined by DSCCrystallinity, where the numerical values of T_(m) and H_(f) correspondto the relationship:

T _(m)≧(0.2143*H _(f))+79.643, preferably T _(m)≧(0.2143*H _(f))+81

and wherein the ethylenic polymer has less than about 1 mole percenthexene comonomer, and less than about 0.5 mole percent butene, pentene,or octene comonomer, preferably less than about 0.1 mole percent butene,pentene, or octene comonomer.

The ethylenic polymer can have a heat of fusion of the ethylenic polymerof less than about 170 J/g and/or a peak melting temperature of theethylenic polymer of less than 126° C. Preferably the ethylenic polymercomprises no appreciable methyl and/or propyl branches as determined byNuclear Magnetic Resonance. The ethylenic polymer preferably comprisesno greater than 2.0 units of amyl groups per 1000 carbon atoms asdetermined by Nuclear Magnetic Resonance.

In another embodiment, an ethylenic polymer is claimed comprising atleast one preparative TREF fraction that elutes at 95° C. or greaterusing a Preparative Temperature Rising Elution Fractionation method,where at least one preparative TREF fraction that elutes at 95° C. orgreater has a branching level greater than about 2 methyls per 1000carbon atoms as determined by Methyls per 1000 Carbons Determination onP-TREF Fractions, and where at least 5 weight percent of the ethylenicpolymer elutes at a temperature of 95° C. or greater based upon thetotal weight of the ethylenic polymer.

In a third embodiment, an ethylenic polymer is claimed comprising atleast one preparative TREF fraction that elutes at 95° C. or greaterusing a Preparative Temperature Rising Elution Fractionation method,where at least one preparative TREF fraction that elutes at 95° C. orgreater has a g′ value of less than 1, preferably less than 0.95, asdetermined by g′ by 3D-GPC, and where at least 5 weight percent of theethylenic polymer elutes at a temperature of 95° C. or greater basedupon the total weight of the ethylenic polymer.

In a fourth embodiment, an ethylenic polymer is claimed comprising atleast one preparative TREF fraction that elutes at 95° C. or greaterusing a Preparative Temperature Rising Elution Fractionation method,where at least one preparative TREF fraction that elutes at 95° C. orgreater has a gpcBR value greater than 0.05 and less than 5 asdetermined by gpcBR Branching Index by 3D-GPC, and where at least 5weight percent of the ethylenic polymer elutes at a temperature of 95°C. or greater based upon the total weight of the ethylenic polymer.

In a fifth embodiment, an ethylenic polymer is claimed comprising atleast one preparative TREF fraction that elutes at 90° C. or greaterusing a Preparative Temperature Rising Elution Fractionation method,where at least one preparative TREF fraction that elutes at 90° C. orgreater has a branching level greater than about 2 methyls per 1000carbon atoms as determined by Methyls per 1000 Carbons Determination onP-TREF Fractions, and where at least 7.5 weight percent of the ethylenicpolymer elutes at a temperature of 90° C. or greater based upon thetotal weight of the ethylenic polymer.

In a sixth embodiment, an ethylenic polymer is claimed comprising atleast one preparative TREF fraction that elutes at 90° C. or greaterusing a Preparative Temperature Rising Elution Fractionation method,where at least one preparative TREF fraction that elutes at 90° C. orgreater has a g′ value of less than 1, preferably less than 0.95, asdetermined by g′ by 3D-GPC, and where at least 7.5 weight percent of theethylenic polymer elutes at a temperature of 90° C. or greater basedupon the total weight of the ethylenic polymer.

In a seventh embodiment, an ethylenic polymer is claimed comprising atleast one preparative TREF fraction that elutes at 90° C. or greaterusing a Preparative Temperature Rising Elution Fractionation method,where at least one preparative TREF fraction that elutes at 90° C. orgreater has a gpcBR value greater than 0.05 and less than 5 asdetermined by gpcBR Branching Index by 3D-GPC, and where at least 7.5weight percent of the ethylenic polymer elutes at a temperature of 90°C. or greater based upon the total weight of the ethylenic polymer.

Finally, a process for making such ethylenic polymers is claimed, saidprocess comprising:

-   -   A) polymerizing ethylene in the presence of a catalyst to form a        linear ethylene-based polymer having a crystallinity of at least        50% as determined by DSC Crystallinity in a first reactor or a        first part of a multi-part reactor; and    -   B) reacting the linear ethylene-based polymer with additional        ethylene in the presence of a free-radical initiator to form an        ethylenic polymer in at least one other reactor or a later part        of a multi-part reactor.

Preferably, the reaction of step (B) occurs by graft polymerization.

Also preferably, the catalyst of step (A) can be a metallocene catalyst.If polar compounds are present in the reaction process, such as beingpresent in the first reactor or the first part of a multi-part reactor,such polar compounds do not inhibit the activity of the metallocenecatalyst.

DESCRIPTION OF THE DRAWINGS

The foregoing summary as well as the following detailed description willbe better understood when read in conjunction with the appendeddrawings. It should be understood, however, that the invention is notlimited to the precise arrangements and instrumentalities shown. Thecomponents in the drawings are not necessarily to scale, with emphasisinstead being placed upon clearly illustrating the principles of thepresent invention. Moreover, in the drawings, like reference numeralsdesignate corresponding parts throughout the several views.

FIGS. 1A-D are schematics illustrating the steps of formation of theinventive ethylenic polymer 400 from a linear ethylene-based polymer100.

FIG. 2 is a plot of a relationship between density and heat of fusionfor 30 Commercially Available Resins of low density polyethylene (LDPE).

FIG. 3 is a plot of heat flow versus temperature as determined by DSCCrystallinity analysis for Example 1, Comparative Example 1 (CE 1), andPolymer 2 (P 2).

FIG. 4 is a plot of heat flow versus temperature as determined by DSCCrystallinity analysis of Example 2, Comparative Example 1 (CE 1), andPolymer 1 (P1).

FIG. 5 is a plot of temperature versus weight percent of polymer sampleeluted as determined by Analytical Temperature Rising ElutionFractionation analysis of Example 1 and Comparative Example 1.

FIG. 6 is a plot of temperature versus weight percent of polymer sampleeluted as determined by Analytical Temperature Rising ElutionFractionation analysis of Example 2, Comparative Example 1, and Polymer1.

FIG. 7 is a plot of maximum peak melting temperature versus heat offusion for Examples 1-5, Comparative Examples 1 and 2, and CommerciallyAvailable Resins 1-30, and a linear demarcation between the Examples,the Comparative Examples, and the Commercially Available Resins.

FIG. 8 represents the temperature splits for Fractions A-D using thePreparative Temperature Rising Elution Fractionation method on Example3.

FIG. 9 represents the temperature splits for combined Fractions AB andCD of Example 3.

FIG. 10 represents the weight percentage of Fraction AB and CD forExample 3-5.

FIG. 11 is a plot of methyls per 1000 carbons (corrected for chain ends)versus weight average elution temperature as determined by Methyls per1000 Carbons Determination on P-TREF Fractions analysis of Fractions ABand CD for Examples 3-5.

FIG. 12 represents a schematic of a cross-fractionation instrument forperforming Cross-Fractionation by TREF analysis.

FIGS. 13 (a & b) and (c & d) are 3D and 2D infra red (IR) responsecurves for weight fraction eluted versus log molecular weight and ATREFtemperature using the Cross-Fractionation by TREF method. FIGS. 13 (a &b) represent a 33:67 weight percent physical blend of Polymer 3 andComparative Example 2. FIGS. 13 (c & d) represent 3D & 2D views,respectively, for an IR response curve of Example 5. FIGS. 13( a) and(b) show discrete components for the blend sample, while FIGS. 13( c)and (d) show a continuous fraction (with no discrete components).

DETAILED DESCRIPTION

The following discussion is presented to enable a person skilled in theart to make and use the disclosed compositions and methods. The generalprinciples described may be applied to embodiments and applicationsother than those detailed without departing from the spirit and scope ofthe disclosed compositions and methods. The disclosed compositions andmethods are not intended to be limited to the embodiments shown, but isto be accorded the widest scope consistent with the principles andfeatures disclosed.

Currently, when a high crystallinity, ethylene-based polymer is usedwith a low crystallinity, highly long chain branched ethylene-basedpolymer, there is no mechanical means to create a blend that faithfullycombines all the physical performance advantages of the ethylene-basedpolymer with the all the favorable processing characteristics of thehighly long chain branched ethylene-based polymer. Disclosed arecompositions and methods that address this shortcoming.

In order to achieve an improvement of physical properties over and abovea mere physical blend of a ethylene-based polymer with a highly branchedethylene-based polymer, it was found that bonding the two separateconstituents—an ethylene-based polymer and a highly long chain branchedethylene-based polymer—results in an ethylenic polymer material withphysical properties akin to or better than the ethylene-based polymercomponent while maintaining processability characteristics akin to thehighly long chain branched ethylene-based polymer component. It isbelieved that the disclosed ethylenic polymer structure is comprised ofhighly branched ethylene-based polymer substituents grafted to orfree-radical polymerization generated ethylene-based long chain polymerbranches originating from a radicalized site on the ethylene-basedpolymer. The disclosed composition is an ethylenic polymer comprised ofan ethylene-based polymer with long chain branches of highly long chainbranched ethylene-based polymer.

The combination of physical and processing properties for the disclosedethylenic polymer is not observed in mere blends of ethylene-basedpolymers with highly long chain branched ethylene-based polymers. Theunique chemical structure of the disclosed ethylenic polymer isadvantageous as the ethylene-based polymer and the highly long chainbranched ethylene-based polymer substituent are linked. When bonded, thetwo different crystallinity materials produce a polymer materialdifferent than a mere blend of the constituents. The combination of twodifferent sets of branching and crystallinity materials results in anethylenic polymer with physical properties that are better than thehighly long chain branched ethylene-based polymer and betterprocessability than the ethylene-based polymer.

The melt index of the disclosed ethylenic polymer may be from about 0.01to about 1000 g/10 minutes, as measured by ASTM 1238-04 (2.16 kg and190° C.).

Ethylene-Based Polymers

Suitable ethylene-based polymers can be prepared with Ziegler-Nattacatalysts, metallocene or vanadium-based single-site catalysts, orconstrained geometry single-site catalysts. Examples of linearethylene-based polymers include high density polyethylene (HDPE) andlinear low density polyethylene (LLDPE). Suitable polyolefins include,but are not limited to, ethylene/diene interpolymers, ethylene/α-olefininterpolymers, ethylene homopolymers, and blends thereof.

Suitable heterogeneous linear ethylene-based polymers include linear lowdensity polyethylene (LLDPE), ultra low density polyethylene (ULDPE),and very low density polyethylene (VLDPE). For example, someinterpolymers produced using a Ziegler-Natta catalyst have a density ofabout 0.89 to about 0.94 g/cm³ and have a melt index (I₂) from about0.01 to about 1,000 g/10 minutes, as measured by ASTM 1238-04 (2.16 kgand 190° C.). Preferably, the melt index (I₂) is from about 0.1 to about50 g/10 minutes. Heterogeneous linear ethylene-based polymers may have amolecular weight distributions, M_(w)/M_(n), from about 3.5 to about4.5.

The linear ethylene-based polymer may comprise units derived from one ormore α-olefin copolymers as long as there is at least 50 mole percentpolymerized ethylene monomer in the polymer.

High density polyethylene (HDPE) may have a density in the range ofabout 0.94 to about 0.97 g/cm³. HDPE is typically a homopolymer ofethylene or an interpolymer of ethylene and low levels of one or moreα-olefin copolymers. HDPE contains relatively few branch chains relativeto the various copolymers of ethylene and one or more α-olefincopolymers. HDPE can be comprised of less than 5 mole % of the unitsderived from one or more α-olefin comonomers

Linear ethylene-based polymers such as linear low density polyethyleneand ultra low density polyethylene (ULDPE) are characterized by anabsence of long chain branching, in contrast to conventional lowcrystallinity, highly branched ethylene-based polymers such as LDPE.Heterogeneous linear ethylene-based polymers such as LLDPE can beprepared via solution, slurry, or gas phase polymerization of ethyleneand one or more α-olefin comonomers in the presence of a Ziegler-Nattacatalyst, by processes such as are disclosed in U.S. Pat. No. 4,076,698(Anderson, et al.). Relevant discussions of both of these classes ofmaterials, and their methods of preparation are found in U.S. Pat. No.4,950,541 (Tabor, et al.).

An α-olefin comonomer may have, for example, from 3 to 20 carbon atoms.Preferably, the α-olefin comonomer may have 3 to 8 carbon atoms.Exemplary α-olefin comonomers include, but are not limited to,propylene, 1-butene, 3-methyl-1-butene, 1-pentene, 3-methyl-1-pentene,4-methyl-1-pentene, 1-hexene, 1-heptene, 4,4-dimethyl-1-pentene,3-ethyl-1-pentene, 1-octene, 1-nonene, 1-decene, 1-dodecene,1-tetradecene, 1-hexadecene, 1-octadecene and 1-eicosene. Commercialexamples of linear ethylene-based polymers that are interpolymersinclude ATTANE™ Ultra Low Density Linear Polyethylene Copolymer, DOWLEX™Polyethylene Resins, and FLEXOMER™ Very Low Density Polyethylene, allavailable from The Dow Chemical Company.

A copolymer may incoporate an α,ω-olefin comonomer. Examples ofstraight-chain or branched acyclic diene compounds that may be used asan α,ω-olefin comonomer include 1,6-heptadiene, 1,7-octadiene,1,8-nonadiene, 1,9-decadiene, 1,11-dodecadiene, 1,13-tetradecadiene, andlower alkyl substituted derivatives thereof; examples of the monocyclicalicyclic diene compounds include 1,3-divinylcyclopentane,1,2-divinylcyclohexane, 1,3-divinylcyclohexane, 1,4-divinylcyclohexane,1,5-divinylcyclooctane, 1-allyl-4-vinylcyclohexane,1,4-diallylcyclohexane, 1-allyl-5-vinyl-cyclooctane,1,5-diallylcyclooctane, and lower alkyl substituted derivatives thereof.Other suitable dienes include bicyclo-(2,2,1)-hepta-2,5-diene(norbornadiene), the dimer of norbornadiene, and diolefins having twostrained ring double bonds, such as the reaction product obtained byreacting 2,5-norbornadiene withcyclopentadienyl-1,4,4a,5,8,8a-hexahydro-1,4,5,8-dimethano-naphthalene.Compounds similar but resulting from the addition of more bridged ringunits by further condensation with cyclopentadiene can also be used.

In a further aspect, when used in reference to an ethylene homopolymer(that is, a high density ethylene homopolymer not containing anycomonomer and thus no short chain branches), the terms “homogeneousethylene polymer” or “homogeneous linear ethylene polymer” may be usedto describe such a polymer.

In one aspect, the term “substantially linear ethylene polymer” as usedrefers to homogeneously branched ethylene polymers that have long chainbranching. The term does not refer to heterogeneously or homogeneouslybranched ethylene polymers that have a linear polymer backbone. Forsubstantially linear ethylene polymers, the long chain branches haveabout the same comonomer distribution as the polymer backbone, and thelong chain branches can be as long as about the same length as thelength of the polymer backbone to which they are attached. The polymerbackbone of substantially linear ethylene polymers is substituted withabout 0.01 long chain branches/1000 carbons to about 3 long chainbranches/1000 carbons, more preferably from about 0.01 long chainbranches/1000 carbons to about 1 long chain branches/1000 carbons, andespecially from about 0.05 long chain branches/1000 carbons to about 1long chain branches/1000 carbons.

Homogeneously branched ethylene polymers are homogeneous ethylenepolymers that possess short chain branches and that are characterized bya relatively high composition distribution breadth index (CDBI). Thatis, the ethylene polymer has a CDBI greater than or equal to 50 percent,preferably greater than or equal to 70 percent, more preferably greaterthan or equal to 90 percent and essentially lack a measurable highdensity (crystalline) polymer fraction.

The CDBI is defined as the weight percent of the polymer moleculeshaving a co-monomer content within 50 percent of the median total molarco-monomer content and represents a comparison of the co-monomerdistribution in the polymer to the co-monomer distribution expected fora Bernoullian distribution. The CDBI of polyolefins can be convenientlycalculated from data obtained from techniques known in the art, such as,for example, temperature rising elution fractionation (“TREF”) asdescribed, for example, by Wild, et al., Journal of Polymer Science,Poly. Phys, Ed., Vol. 20, 441 (1982); L. D. Cady, “The Role of ComonomerType and Distribution in LLDPE Product Performance,” SPE RegionalTechnical Conference, Quaker Square Hilton, Akron, Ohio. 107-119 (Oct.1-2, 1985); or in U.S. Pat. No. 4,798,081 (Hazlitt, et al.) and U.S.Pat. No. 5,008,204 (Stehling). However, the TREE technique does notinclude purge quantities in CDBI calculations. More preferably, theco-monomer distribution of the polymer is determined using ¹³C NMRanalysis in accordance with techniques described, for example, in U.S.Pat. No. 5,292,845 (Kawasaki, et al.) and by J. C. Randall in Rev.Macromol. Chem. Phys., C29, 201-317.

The terms “homogeneously branched linear ethylene polymer” and“homogeneously branched linear ethylene/α-olefin polymer” means that theolefin polymer has a homogeneous or narrow short branching distribution(that is, the polymer has a relatively high CDBI) but does not have longchain branching. That is, the linear ethylene-based polymer is ahomogeneous ethylene polymer characterized by an absence of long chainbranching. Such polymers can be made using polymerization processes (forexample, as described by Elston) which provide a uniform short chainbranching distribution (homogeneously branched). In the polymerizationprocess described by Elston, soluble vanadium catalyst systems are usedto make such polymers; however, others, such as Mitsui PetrochemicalIndustries and Exxon Chemical Company, have reportedly used so-calledsingle site catalyst systems to make polymers having a homogeneousstructure similar to polymer described by Elston, Further, Ewen, et al.,and U.S. Pat. No. 5,218,071 (Tsutsui, et al.) disclose the use ofmetallocene catalysts for the preparation of homogeneously branchedlinear ethylene polymers. Homogeneously branched linear ethylenepolymers are typically characterized as having a molecular weightdistribution, M_(w)/M_(n), of less than 3, preferably less than 2.8,more preferably less than 2.3.

In discussing linear ethylene-based polymers, the terms “homogeneouslybranched linear ethylene polymer” or “homogeneously branched linearethylene/α-olefin polymer” do not refer to high pressure branchedpolyethylene which is known to those skilled in the art to have numerouslong chain branches. In one aspect, the term “homogeneous linearethylene polymer” generically refers to both linear ethylenehomopolymers and to linear ethylene/α-olefin interpolymers. For example,a linear ethylene/α-olefin interpolymer possess short chain branchingand the α-olefin is typically at least one C₃-C₂₀, α-olefin (forexample, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene,and 1-octene).

The presence of long chain branching can be determined in ethylenehomopolymers by using ¹³C nuclear magnetic resonance (NMR) spectroscopyand is quantified using the method described by Randall (Rev. Macromol.Chem. Phys., C29, V. 2&3, 285-297). There are other known techniquesuseful for determining the presence of long chain branches in ethylenepolymers, including ethylene/1-octene interpolymers. Two such exemplarymethods are gel permeation chromatography coupled with a low angle laserlight scattering detector (GPC-LALLS) and gel permeation chromatographycoupled with a differential viscometer detector (GPC-DV). The use ofthese techniques for long chain branch detection and the underlyingtheories have been well documented in the literature, See, for example,Zimm, G. H. and Stockmayer, W. H., J. Chem. Phys., 17, 1301 (1949), andRudin, A., Modern Methods of Polymer Characterization, John Wiley &Sons, New York (1991) 103-112.

In a further aspect, substantially linear ethylene polymers arehomogeneously branched ethylene polymers and are disclosed in both U.S.Pat. Nos. 5,272,236 and 5,278,272 (both Lai, et al.), Homogeneouslybranched substantially linear ethylene polymers are available from TheDow Chemical Company of Midland, Mich. as AFFINITY™ polyolefinplastomers and ENGAGE™ polyolefin elastomers, Homogeneously branchedsubstantially linear ethylene polymers can be prepared via the solution,slurry, or gas phase polymerization of ethylene and one or more optionalα-olefin comonomers in the presence of a constrained geometry catalyst,such as the method disclosed in European Patent 0416815 (Stevens, etal.).

The terms “heterogeneous” and “heterogeneously branched” mean that theethylene polymer can be characterized as a mixture of interpolymermolecules having various ethylene to comonomer molar ratios.Heterogeneously branched linear ethylene polymers are available from TheDow Chemical Company as DOWLEX™ linear low density polyethylene and asATTANE™ ultra-low density polyethylene resins. Heterogeneously branchedlinear ethylene polymers can be prepared via the solution, slurry or gasphase polymerization of ethylene and one or more optional α-olefincomonomers in the presence of a Ziegler Natta catalyst, by processessuch as are disclosed in U.S. Pat. No. 4,076,698 (Anderson, et al.).Heterogeneously branched ethylene polymers are typically characterizedas having molecular weight distributions, Mw/Mn, from about 3.5 to about4.1 and, as such, are distinct from substantially linear ethylenepolymers and homogeneously branched linear ethylene polymers in regardsto both compositional short chain branching distribution and molecularweight distribution.

The Brookfield viscosity of the ethylene-based polymers is from about 20to about 55,000,000 cP as measured at 177° C. using the BrookfieldViscosity method as described in the Test Methods section.

Overall, the high crystallinity, ethylene-based polymers have a densityof greater than or equal to about 0.89 g/cm3, preferably greater than orequal to about 0.91 g/cm3, and preferably less than or equal to about0.97 g/cm3. Preferably, these polymers have a density from about 0.89 toabout 0.97 g/cm3. All densities are determined by the Density method asdescribed in the Test Methods section.

Highly Long Chain Branched Ethylene-Based Polymers

Highly long chain branched ethylene-based polymers, such as low densitypolyethylene (LDPE), can be made using a high-pressure process usingfree-radical chemistry to polymerize ethylene monomer. Typical polymerdensity is from about 0.91 to about 0.94 g/cm³. The low densitypolyethylene may have a melt index (I₂) from about 0.01 to about 150g/10 minutes. Highly long chain branched ethylene-based polymers such asLDPE may also be referred to as “high pressure ethylene polymers”,meaning that the polymer is partly or entirely homopolymerized orcopolymerized in autoclave or tubular reactors at pressures above 13,000psig with the use of free-radical initiators, such as peroxides (see,for example, U.S. Pat. No. 4,599,392 (McKinney, et al.)). The processcreates a polymer with significant branches, including long chainbranches.

Highly long chain branched ethylene-based polymers are typicallyhomopolymers of ethylene; however, the polymer may comprise unitsderived from one or more α-olefin copolymers as long as there is atleast 50 mole percent polymerized ethylene monomer in the polymer.

Comonomers that may be used in forming highly branched ethylene-basedpolymer include, but are not limited to, α-olefin comonomers, typicallyhaving no more than 20 carbon atoms. For example, the α-olefincomonomers, for example, may have 3 to 10 carbon atoms; or in thealternative, the α-olefin comonomers, for example, may have 3 to 8carbon atoms. Exemplary α-olefin comonomers include, but are not limitedto, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene,1-nonene, 1-decene, and 4-methyl-1-pentene. In the alternative,exemplary comonomers include, but are not limited to α, β-unsaturatedC₃-C₈-carboxylic acids, in particular maleic acid, fumaric acid,itaconic acid, acrylic acid, methacrylic acid and crotonic acidderivates of the α, β-unsaturated C₃-C₈-carboxylic acids, for exampleunsaturated C₃-C₁₅-carboxylic acid esters, in particular ester ofC₁-C₆-alkanols, or anhydrides, in particular methyl methacrylate, ethylmethacrylate, n-butyl methacrylate, ter-butyl methacrylate, methylacrylate, ethyl acrylate n-butyl acrylate, 2-ethylhexyl acrylate,tert-butyl acrylate, methacrylic anhydride, maleic anhydride, anditaconic anhydride. In another alternative, the exemplary comonomersinclude, but are not limited to, vinyl carboxylates, for example vinylacetate. In another alternative, exemplary comonomers include, but arenot limited to, n-butyl acrylate, acrylic acid and methacrylic acid.

Process

The ethylene-based polymer may be produced before or separately from thereaction process with the highly branched ethylene-based polymer. Inother disclosed processes, the ethylene-based polymer may be formed insitu and in the presence of highly branched ethylene-based polymerwithin a well-stirred reactor such as a tubular reactor or an autoclavereactor. The highly long chain branched ethylene-based polymer is formedin the presence of ethylene.

The ethylenic polymer is formed in the presence of ethylene. FIG. 1 givea general representation of free-radical ethylene polymerization to forma long chain branch from a radicalized linear ethylene-based polymersite of forming embodiment ethylenic polymers. Other embodimentprocesses for formation of the ethylene-based polymer, the substituenthighly branched ethylene-based polymer, and their combination into thedisclosed ethylenic polymer may exist.

In a first step of an embodiment process, an ethylene-based polymer 100,as shown in FIG. 1A, is formed. Ethylene-based polymer 100 may be formedby several different polymer processes, including, but not limited to, agas-phase polymerization process, a slurry polymerization process, and asolution-based polymerization process. In some embodiments, theethylene-based polymer 100 is formed in a separate process. Examples ofpolymers that may take the form of a ethylene-based polymer 100 includeHDPE, LLDPE, ULDPE, and VLDPE.

In a second step of an embodiment process, the ethylene-based polymer100 further comprises an extractable hydrogen 101 as shown in FIG. 1B.The ethylene-based polymer 100 enters an area, such as a reactor, inwhich free-radical polymerization of ethylene monomer 200 into a highlylong chain branched ethylene-based polymer 300 is supported.

At some point during this step, a free-radical bearing molecule, such asa peroxide initiator breakdown product or a growing, highly long chainbranched ethylene-based polymer chain 301, interacts with theethylene-based polymer 100 by extracting the extractable hydrogen 101and transfers the free radical to the ethylene-based polymer 100.Methods for extracting the extractable hydrogen 101 from theethylene-based polymer 100 include, but are not limited to, reactionwith free radicals which are generated by homolytically cleavingmolecules (for instance, peroxide-containing compounds or azo-containingcompounds) or by external radiation.

In a third step of an embodiment process, the ethylene-based polymer 100further comprises a radicalized site 102 after hydrogen extraction, asshown in FIG. 1C. At this point in the process, and in the presence ofethylene, either a growing, highly long chain branched ethylene-basedpolymer chain 301 or ethylene monomer 200 interacts with the radicalizedsite 102 to attach to (via termination) or form a long chain branch(through polymerization). The reactions between FIGS. 1B and 1C mayoccur several times with the same ethylene-based polymer.

FIG. 1D shows a representation of an embodiment ethylenic polymer 400.Linear portion 401 of the embodiment ethylenic polymer 400 is theportion of the resultant polymer that does not contain a number of longchain branches 403. The branched portion 402 of the disclosed ethylenicpolymer 400 is the portion of the resultant polymer that does contain anumber of long chain branches 403.

In an embodiment process, the ethylene-based polymer is preparedexternally to the reaction process used to form the embodiment ethylenicpolymer, combined in a common reactor in the presence of ethylene underfree-radical polymerization conditions, and subjected to processconditions and reactants to effect the formation of the embodimentethylenic polymer.

In another embodiment process, the highly long chain branchedethylene-based polymer and the ethylene-based polymer are both preparedin different forward parts of the same process and are then combinedtogether in a common downstream part of the process in the presence ofethylene under free-radical polymerization conditions. Theethylene-based polymer and the substituent highly long chain branchedethylene-based polymer are made in separate forward reaction areas orzones, such as separate autoclaves or an upstream part of a tubularreactor. The products from these forward reaction areas or zones arethen transported to and combined in a downstream reaction area or zonein the presence of ethylene under free-radical polymerization conditionsto facilitate the formation of an embodiment ethylenic polymer. In someprocesses, additional fresh ethylene is added to the process downstreamof the forward reaction areas or zones to facilitate both the formationof and grafting of highly long chain branched ethylene-based polymers tothe ethylene-based polymer and the reaction of ethylene monomer directlywith the ethylene-based polymer to form the disclosed ethylenic polymer.In some other processes, at least one of the product streams from theforward reaction areas or zones is treated before reaching thedownstream reaction area or zone to neutralize any residue or byproductsthat may inhibit the downstream reactions.

In an embodiment in situ process, the ethylene-based polymer is createdin a first or forward reaction area or zone, such as a first autoclaveor an upstream part of a tubular reactor. The resultant product streamis then transported to a downstream reaction area or zone where there isa presence of ethylene at free-radical polymerization conditions. Theseconditions support both the formation of and grafting of highly longchain branched ethylene-based polymer to the ethylene-based polymer,thereby forming an embodiment ethylenic polymer. In some embodimentprocesses, free radical generating compounds are added to the downstreamreaction area or zone to facilitate the grafting reaction. In some otherembodiment processes, additional fresh ethylene is added to the processdownstream of the forward reaction areas or zones to facilitate both theformation and grafting of highly long chain branched ethylene-basedpolymer to and the reaction of ethylene monomer with the ethylene-basedpolymer to form the disclosed ethylenic polymer. In some embodimentprocesses, the product stream from the forward reaction area or zone istreated before reaching the downstream reaction area or zone toneutralize any residue or byproducts from the previous reaction that mayinhibit the highly branched ethylene-based polymer formation, thegrafting of highly long chain branched ethylene-based polymer to theethylene-based polymer, or the reaction of ethylene monomer with theethylene-based polymer to form the disclosed ethylenic polymer.

For producing the ethylene-based polymer, a gas-phase polymerizationprocess may be used. The gas-phase polymerization reaction typicallyoccurs at low pressures with gaseous ethylene, hydrogen, a catalystsystem, for example a titanium containing catalyst, and, optionally, oneor more comonomers, continuously fed to a fluidized-bed reactor. Such asystem typically operates at a pressure from about 300 to about 350 psiand a temperature from about 80 to about 100° C.

For producing the ethylene-based polymer, a solution-phasepolymerization process may be used. Typically such a process occurs in awell-stirred reactor such as a loop reactor or a sphere reactor attemperature from about 150 to about 575° C., preferably from about 175to about 205° C., and at pressures from about 30 to about 1000 psi,preferably from about 30 to about 750 psi. The residence time in such aprocess is from about 2 to about 20 minutes, preferably from about 10 toabout 20 minutes. Ethylene, solvent, catalyst, and optionally one ormore comonomers are fed continuously to the reactor. Exemplary catalystsin these embodiments include, but are not limited to, Ziegler-Natta,constrained geometry, and metallocene catalysts. Exemplary solventsinclude, but are not limited to, isoparaffins. For example, suchsolvents are commercially available under the name ISOPAR E (ExxonMobilChemical Co., Houston, Tex.). The resultant mixture of ethylene-basedpolymer and solvent is then removed from the reactor and the polymer isisolated. Solvent is typically recovered via a solvent recovery unit,that is, heat exchangers and vapor liquid separator drum, and isrecycled back into the polymerization system.

Any suitable method may be used for feeding the ethylene-based polymerinto a reactor where it may be reacted with a highly long chain branchedethylene-based polymer. For example, in the cases where theethylene-based polymer is produced using a gas phase process, theethylene-based polymer may be dissolved in ethylene at a pressure abovethe highly long chain branched ethylene-based polymer reactor pressure,at a temperature at least high enough to dissolve the ethylene-basedpolymer and at concentration which does not lead to excessive viscositybefore feeding to the highly long chain branched ethylene-based polymerreactor.

For producing the highly long chain branched ethylene-based polymer, ahigh pressure, free-radical initiated polymerization process istypically used. Two different high pressure free-radical initiatedpolymerization process types are known. In the first type, an agitatedautoclave vessel having one or more reaction zones is used. Theautoclave reactor normally has several injection points for initiator ormonomer feeds, or both. In the second type, a jacketed tube is used as areactor, which has one or more reaction zones. Suitable, but notlimiting, reactor lengths may be from about 100 to about 3000 meters,preferably from about 1000 to about 2000 meters. The beginning of areaction zone for either type of reactor is defined by the sideinjection of either initiator of the reaction, ethylene, telomer,comonomer(s) as well as any combination thereof. A high pressure processcan be carried out in autoclave or tubular reactors or in a combinationof autoclave and tubular reactors, each comprising one or more reactionzones.

In embodiment processes, the catalyst or initiator is injected prior tothe reaction zone where free radical polymerization is to be induced. Inother embodiment processes, the ethylene-based polymer may be fed intothe reaction system at the front of the reactor system and not formedwithin the system itself. Termination of catalyst activity may beachieved by a combination of high reactor temperatures for the freeradical polymerization portion of the reaction or by feeding initiatorinto the reactor dissolved in a mixture of a polar solvent such asisopropanol, water, or conventional initiator solvents such as branchedor unbranched alkanes.

Embodiment processes may include a process recycle loop to improveconversion efficiency. In some embodiment processes, the recycle loopmay be treated to neutralize residues or byproducts from the previousreaction cycle that may inhibit polymerization of either theethylene-based polymer or the highly long chain branched ethylene-basedpolymer or inhibit the reaction forming the disclosed ethylenic polymer.In some embodiment processes, fresh monomer is added to this stream.

Ethylene used for the production of ethylene-based polymers or highlylong chain branched ethylene-based polymer may be purified ethylene,which is obtained by removing polar components from a loop recyclestream or by using a reaction system configuration such that only freshethylene is used for making the ethylene-based polymers. It is nottypical that purified ethylene is required to make highly long chainbranched ethylene-based polymer. In such cases ethylene from the recycleloop may be used.

Embodiment processes may be used for either the homopolymerization ofethylene in the presence of an ethylene-based polymer orcopolymerization of ethylene with one or more other comonomers in thepresence of an ethylene-based polymer, provided that these monomers arecopolymerizable with ethylene under free-radical conditions in highpressure conditions to form highly long chain branched ethylene-basedpolymers.

Chain transfer agents or telogens (CTA) are typically used to controlthe melt index in a free-radical polymerization process. Chain transferinvolves the termination of growing polymer chains, thus limiting theultimate molecular weight of the polymer material. Chain transfer agentsare typically hydrogen atom donors that will react with a growingpolymer chain and stop the polymerization reaction of the chain. Forhigh pressure free radical polymerization, these agents can be of manydifferent types, such as saturated hydrocarbons, unsaturatedhydrocarbons, aldehydes, ketones or alcohols. Typical CTAs that can beused include, but are not limited to, propylene, isobutane, n-butane,1-butene, methyl ethyl ketone, propionaldehyde, ISOPAR (ExxonMobilChemical Co.), and isopropanol. The amount of CTAs to use in the processis about 0.03 to about 10 weight percent of the total reaction mixture.

The melt index (MI or I₂) of a polymer, which is inversely related tothe molecular weight, is controlled by manipulating the concentration ofthe chain transfer agent. For free radical polymerization, after thedonation of a hydrogen atom, the CTA forms a radical which can reactwith the monomers, or with an already formed oligomers or polymers, tostart a new polymer chain. This means that any functional groups presentin the chain transfer agents will be introduced in the polymer chains. Alarge number of CTAs, for example, propylene and 1-butene which have anolefinically unsaturated bond, may also be incorporated in the polymerchain themselves, via a copolymerization reaction. Polymers produced inthe presence of chain transfer agents are modified in a number ofphysical properties such as processability, optical properties such ashaze and clarity, density, stiffness, yield point, film draw and tearstrength.

Hydrogen has been shown to be a chain transfer agent for high pressurefree radical polymerization and in the production of the highcrystallinity ethylene-based polymer. Control of the molecular weightmade in the reaction zones for disclosed processes may be accomplishedby feeding hydrogen to the reaction zones where catalyst or initiator isinjected. The final product melt index control would be accomplished byfeeding chain transfer agents to the reaction zones where free radicalpolymerization takes place. Feed of the free radical chain transferagents could be accomplished by direct injection into the reaction zonesor by feeding them to the front of the reactor. In some embodimentprocesses, it may be necessary to remove excess CTA from the recyclestream or limit injection so as to prevent excess buildup of CTA in thefront end of the process.

Free radical initiators that are generally used to produceethylene-based polymers are oxygen, which is usable in tubular reactorsin conventional amounts of between 0.0001 and 0.005 wt. % drawn to theweight of polymerizable monomer, and peroxides. Preferred initiators aret-butyl peroxy pivalate, di-t-butyl peroxide, t-butyl peroxy acetate andt-butyl peroxy-2-hexanoate or mixtures thereof. These organic peroxyinitiators are used in conventional amounts of between 0.005 and 0.2 wt.% drawn to the weight of polymerizable monomers.

The peroxide initiator may be, for example, an organic peroxide.Exemplary organic peroxides include, but are not limited to, cyclicperoxides, diacyl peroxides, dialkyl peroxides, hydroperoxides,peroxycarbonates, peroxydicarbonates, peroxyesters, and peroxyketals.

Exemplary cyclic peroxides include, but are not limited to,3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxonane. Such cyclicperoxides, for example, are commercially available under the tradenameTRIGONOX 301 (Akzo Nobel; Arnhem, The Netherlands). Exemplary diacylperoxides include, but are not limited to,di(3,5,5-trimethylhexanoyl)peroxide. Such diacyl peroxides, for example,are commercially available under the tradename TRIGONOX 36 (Akzo Nobel).Exemplary dialkyl peroxides include, but are not limited to,2,5-dimethyl-2,5-di(tert-butylperoxy)hexane;2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3; di-tert-amyl peroxide;di-tert-butyl peroxide; and tert-butyl cumyl peroxide. Such dialkylperoxides, for example, are commercially available under the tradenamesTRIGONOX 101, TRIGONOX 145, TRIGONOX 201, TRIGONOX B, and TRIGONOX T(Akzo Nobel). Exemplary hydroperoxides include, but are not limited to,tert-Amyl hydroperoxide; and 1,1,3,3-tetramethylbutyl hydroperoxide.Such hydroperoxides, for example, are commercially available under thetradenames TRIGONOX TAHP, and TRIGONOX TMBH (Akzo Nobel). Exemplaryperoxycarbonates include, but are not limited to, tert-butylperoxy2-ethylhexyl carbonate; tert-amylperoxy 2-ethylhexyl carbonate; andtert-butylperoxy isopropyl carbonate. Such peroxycarbonates, forexample, are commercially available under the tradenames TRIGONOX 117,TRIGONOX 131, and TRIGONOX BPIC (Akzo Nobel). Exemplaryperoxydicarbonates include, but are not limited to,di(2-ethylhexyl)peroxydicarbonates; and di-sec-butyl peroxydicarbonates.Such peroxydicarbonates, for example, are commercially available underthe tradename TRIGONOX EHP, and TRIGONOX SBP (Akzo Nobel). Exemplaryperoxyesters include, but are not limited to, tert-amylperoxy-2-ethylhexanoate; tert-amyl peroxyneodecanoate; tert-amylperoxypivalate; tert-amyl peroxybenzoate; tert-amyl peroxyacetate;2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane; tert-butylperoxy-2-ethylhexanoate; tert-butyl peroxyneodecanoate; tert-butylperoxyneoheptanoate; tert-butyl peroxypivalate; tert-butylperoxydiethylacetate; tert-butyl peroxyisobutyrate;1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate;1,1,3,3-tetramethylbutyl peroxyneodecanoate; 1,1,3,3-tetramethylbutylperoxypivalate; tert-butyl peroxy-3,5,5-trimethylhexanoate; cumylperoxyneodecanoate; tert-butyl peroxybenzoate; and tert-butylperoxyacetate. Such peroxyesters solvents, for example, are commerciallyavailable under the tradenames TRIGONOX 121; TRIGONOX 123; TRIGONOX 125;TRIGONOX 127; TRIGONOX 133; TRIGONOX 141; TRIGONOX 21; TRIGONOX 23;TRIGONOX 257; TRIGONOX 25; TRIGONOX 27; TRIGONOX 41; TRIGONOX 421;TRIGONOX 423; TRIGONOX 425; TRIGONOX 42; TRIGONOX 99; TRIGONOX C; andTRIGONOX F (Akzo Nobel). Exemplary peroxyketals include, but are notlimited to, 1,1-di(tert-amylperoxy)cyclohexane;1,1-di(tert-butylperoxy)cyclohexane;1,1-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane; and2,2-di(tert-butylperoxy)butane. Such peroxyketals, for example, arecommercially available under the tradenames TRIGONOX 122, TRIGONOX 22,TRIGONOX 29, and TRIGONOX D (Akzo Nobel). The free radical initiatorsystem may, for example, include a mixture or combination of any of theaforementioned peroxide initiators. The peroxide initiator may compriseless than 60 percent by weight the free radical initiator system.

The free radical initiator system further includes at least onehydrocarbon solvent. The hydrocarbon solvent may, for example, be a C₅to C₃₀ hydrocarbon solvent. Exemplary hydrocarbon solvents include, butare not limited to, mineral solvents, normal paraffinic solvents,isoparaffinic solvents, cyclic solvents, and the like. The hydrocarbonsolvents may, for example, be selected from the group consisting ofn-octane, iso-octane (2,2,4-trimethylpentane), n-dodecane, iso-dodecane(2,2,4,6,6-pentamethylheptane), and other isoparaffinic solvents.Exemplary hydrocarbon solvents such as isoparaffinic solvents, forexample, are commercially available under the tradenames ISOPAR C,ISOPAR E, and ISOPAR H (ExxonMobil Chemical Co.). The hydrocarbonsolvent may comprise less than 99 percent by weight of the free radicalinitiator system.

In some embodiment processes, the free radical initiator system mayfurther include a polar co-solvent. The polar co-solvent may be analcohol co-solvent, for example, a C₁ to C₃₀ alcohol. Additionally, thealcohol functionality of the alcohol co-solvent may, for example, bemono-functional or multi-functional. Exemplary alcohols as a polarco-solvent include, but are not limited to, isopropanol (2-propanol),allylalcohol (1-pentanol), methanol, ethanol, propanol, butanol,1,4-butanediol, combinations thereof, mixtures thereof, and the like.The polar co-solvent may comprise less than 40 percent by weight of thefree radical initiator system.

The polar co-solvent may be an aldehyde. Aldehydes are generally knownto a person of skill in the art; for example, propionaldehyde may beused as a polar co-solvent. However, the reactivity potential ofaldehydes as chain transfer agents should be taken into account whenusing such aldehydes as polar co-solvents. Such reactivity potentialsare generally known to a person of skill in the art.

The polar co-solvent may be a ketone. Ketones are generally known to aperson of skill in the art; for example, acetone or tetrahydrofuran maybe used as polar co-solvents. However, the reactivity potential ofketones as chain transfer agents should be taken into account when usingsuch ketones as polar co-solvents. Such reactivity potentials aregenerally known to a person of skill in the art.

In some embodiment processes, the free radical initiator system mayfurther comprise a chain transfer agent as a solvent or as a blend forsimultaneous injection. As previously discussed, chain transfer agentsare generally known to a person of skill in the art, and they include,but are not limited to, propane, isobutane, acetone, propylene,isopropanol, butene-1, propionaldehyde, and methyl ethyl ketone. Inother disclosed processes, chain transfer agent may be charged into thereactor via a separate inlet port from the initiator system. In anotherembodiment process, a chain transfer agent may be blended with ethylene,pressurized, and then injected into the reactor in its own injectionsystem.

In some embodiment processes, a peroxide initiator may initially bedissolved or diluted in a hydrocarbon solvent, and then a polarco-solvent added to the peroxide initiator/hydrocarbon solvent mixtureprior to metering the free radical initiator system into thepolymerization reactor. In another embodiment process, a peroxideinitiator may be dissolved in the hydrocarbon solvent in the presence ofa polar co-solvent.

The free-radical initiator used in the process may initiate the graftsite on the linear ethylene-based polymer by extracting the extractablehydrogen from the linear ethylene-based polymer. Example free-radicalinitiators include those free radical initiators previously discussed,such as peroxides and azo compounds. In some other embodiment processes,ionizing radiation may also be used to free the extractable hydrogen andcreate the radicalized site on the linear ethylene-based polymer.Organic initiators are preferred means of extracting the extractablehydrogen, such as using dicumyl peroxide, di-tert-butyl peroxide,t-butyl perbenzoate, benzoyl peroxide, cumene hydroperoxide, t-butylperoctoate, methyl ethyl ketone peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, lauryl peroxide, and tert-butyl peracetate, t-butylα-cumyl peroxide, di-t-butyl peroxide, di-t-amyl peroxide, t-amylperoxybenzoate, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane,α,α′-bis (t-butylperoxy)-1,3-diisopropylbenzene,α,α′-bis(t-butylperoxy)-1,4-diisopropylbenzene,2,5-bis(t-butylperoxy)-2,5-dimethylhexane, and2,5-bis(t-butylperoxy)-2,5-dimethyl-3-hexyne. A preferred azo compoundis azobisisobutyl nitrite.

Suitable catalysts for use in embodiment processes include any compoundor combination of compounds that is adapted for preparing polymers ofthe desired composition or type, either the ethylene-based polymers orthe highly long chain branched ethylene-based polymers. Bothheterogeneous and homogeneous catalysts, and combinations thereof, maybe employed. In some embodiment processes, heterogeneous catalysts,including the well known Ziegler-Natta compositions, especially Group 4metal halides supported on Group 2 metal halides or mixed halides andalkoxides and the well known chromium or vanadium based catalysts, maybe used. In some embodiment processes, the catalysts for use may behomogeneous catalysts comprising a relatively pure organometalliccompound or metal complex, especially compounds or complexes based onmetals selected from Groups 3-10 or the Lanthanide series. If more thanone catalyst is used in a system, it is preferred that any catalystemployed not significantly detrimentally affect the performance ofanother catalyst under the conditions of polymerization. Desirably, nocatalyst is reduced in activity by greater than 25 percent, morepreferably greater than 10 percent under the conditions of thepolymerization. Examples of preferred catalyst systems may be found inU.S. Pat. Nos. 5,272,236 (Lai, et al.); 5,278,272 (Lai, et al.);6,054,544 (Finlayson, et al.); 6,335,410 (Finlayson, et al.); and6,723,810 (Finlayson, et al.); PCT Publication Nos. WO 2003/091262(Boussie, et al.); 2007/136497 (Konze, et al.); 2007/136506 (Konze, etal.); 2007/136495 (Konze, et al.); and 2007/136496 (Aboelella, et al.).Other suitable catalysts may be found in U.S. Patent Publication No.2007/0167578 (Arriola; et al.).

In some embodiment processes, a coordination-catalysis polymerizationprocess may be used for the formation of the higher crystallinity linearethylene-based polymer. In such embodiment processes, such catalystsystems would have a suitable tolerance to polar impurities that wouldresult from impurities in the ethylene feed and degradation productsfrom free-radical initiators. Control of the amount of polar impuritiesfed to the front portion of the reactor for the target catalystefficiency could be accomplished by controlling the amount of polarsolvent used in the initiator mixture and by the amount of materialcondensed in the process recycle streams. A type of coordinationcatalyst may include constrained geometry catalysts (CGC) as describedin U.S. Pat. Nos. 5,272,236 and 5,278,272. Preferred catalysts in such aCGC system may include the general family of zirconium catalysts withbiphenyl-phenol ligands, includingbis((2-oxoyl-3-(1,1-dimethylethyl)phen-1-yl)-5-(methyl)phenyl)-2-phenoxy)propane-1,2-diylzirconium(IV) dimethyl andbis((2-oxoyl-3-(dibenzo-1H-pyrrole-1-yl)-5-(methyl)phenyl)-2-phenoxy)-trans-cyclohexane-1,2-dimethylenyl-1,2-diylzirconium(IV) dimethyl, because they are known to have a good tolerance to polarimpurities. Free radical initiators that generate carbon radicals reducethe amount of polar impurities in the system and potentially make theuse of more conventional catalysts possible. Examples of carbon-centeredfree radical generators include azo compounds, including but not limitedto, azo-bis-is-butyro-nitrile. Such compounds may have a half-lifedecomposition temperature of about 30 to about 250° C. Carbon-carboninitiators, examples of such include dimethyl diphenyl butane, dimethyldiphenyl hexane, and derivatives thereof, may be used to reach suitablehalf-life times under proscribed operating conditions.

In embodiment processes employing a complex metal catalyst, such acatalyst may be activated to form an active catalyst composition bycombination with a cocatalyst, preferably a cation forming cocatalyst, astrong Lewis acid, or a combination thereof. Suitable cocatalysts foruse include polymeric or oligomeric aluminoxanes, especially methylaluminoxane, as well as inert, compatible, noncoordinating, ion formingcompounds. So-called modified methyl aluminoxane (MMAO) is also suitablefor use as a cocatalyst. One technique for preparing such modifiedaluminoxane is disclosed in U.S. Pat. No. 5,041,584 (Crapo, et al.).Aluminoxanes can also be made as disclosed in U.S. Pat. Nos. 5,542,199(Lai, et al.); 4,544,762 (Kaminsky, et al.); 5,015,749 (Schmidt, etal.); and 5,041,585 (Deavenport, et al.). Other preferred cocatalystsare inert, noncoordinating, boron compounds, such as perfluoroarylborane(B(C₆F₅)₃) and the class of compounds known as (bis-hydrogenatedtallowalkyl)methylammonium tetrakis(pentafluorophenyl)borates, which aremixtures of complexes with the general chemical structure([R₂NCH₃]+[B(C₆F₅)₄]—, wherein R may be a C₁₄, C₁₆ or C₁₈ alkyl. Otherpreferred cocatalysts may be found in U.S. Patent Publication No.2007/0167578.

In some embodiment processes, processing aids, such as plasticizers, canalso be included in the embodiment ethylenic polymer product. These aidsinclude, but are not limited to, the phthalates, such as dioctylphthalate and diisobutyl phthalate, natural oils such as lanolin, andparaffin, naphthenic and aromatic oils obtained from petroleum refining,and liquid resins from rosin or petroleum feedstocks. Exemplary classesof oils useful as processing aids include white mineral oil such asKAYDOL oil (Chemtura Corp.; Middlebury, Conn.) and SHELLFLEX 371naphthenic oil (Shell Lubricants; Houston, Tex.). Another suitable oilis TUFFLO oil (Lyondell Lubricants; Houston, Tex.).

In some embodiment processes, embodiment ethylenic polymers are treatedwith one or more stabilizers, for example, antioxidants, such as IRGANOX1010 and IRGAFOS 168 (Ciba Specialty Chemicals; Glattbrugg,Switzerland). In general, polymers are treated with one or morestabilizers before an extrusion or other melt processes. In otherembodiment processes, other polymeric additives include, but are notlimited to, ultraviolet light absorbers, antistatic agents, pigments,dyes, nucleating agents, fillers, slip agents, fire retardants,plasticizers, processing aids, lubricants, stabilizers, smokeinhibitors, viscosity control agents and anti-blocking agents. Theembodiment ethylenic polymer composition may, for example, comprise lessthan 10 percent by the combined weight of one or more additives, basedon the weight of the embodiment ethylenic polymer.

The embodiment ethylenic polymer may further be compounded. In someembodiment ethylenic polymer compositions, one or more antioxidants mayfurther be compounded into the polymer and the compounded polymerpelletized. The compounded ethylenic polymer may contain any amount ofone or more antioxidants. For example, the compounded ethylenic polymermay comprise from about 200 to about 600 parts of one or more phenolicantioxidants per one million parts of the polymer. In addition, thecompounded ethylenic polymer may comprise from about 800 to about 1200parts of a phosphite-based antioxidant per one million parts of polymer.The compounded disclosed ethylenic polymer may further comprise fromabout 300 to about 1250 parts of calcium stearate per one million partsof polymer.

Uses

The embodiment ethylenic polymer may be employed in a variety ofconventional thermoplastic fabrication processes to produce usefularticles, including objects comprising at least one film layer, such asa monolayer film, or at least one layer in a multilayer film prepared bycast, blown, calendered, or extrusion coating processes; moldedarticles, such as blow molded, injection molded, or rotomolded articles;extrusions; fibers; and woven or non-woven fabrics. Thermoplasticcompositions comprising the embodiment ethylenic polymer include blendswith other natural or synthetic materials, polymers, additives,reinforcing agents, ignition resistant additives, antioxidants,stabilizers, colorants, extenders, crosslinkers, blowing agents, andplasticizers.

The embodiment ethylenic polymer may be used in producing fibers forother applications. Fibers that may be prepared from the embodimentethylenic polymer or blends thereof include staple fibers, tow,multicomponent, sheath/core, twisted, and monofilament. Suitable fiberforming processes include spunbonded and melt blown techniques, asdisclosed in U.S. Pat. Nos. 4,340,563 (Appel, et al.), 4,663,220(Wisneski, et al.), 4,668,566 (Nohr, et al.), and 4,322,027 (Reba), gelspun fibers as disclosed in U.S. Pat. No. 4,413,110 (Kavesh, et al.),woven and nonwoven fabrics, as disclosed in U.S. Pat. No. 3,485,706(May), or structures made from such fibers, including blends with otherfibers, such as polyester, nylon or cotton, thermoformed articles,extruded shapes, including profile extrusions and co-extrusions,calendared articles, and drawn, twisted, or crimped yarns or fibers.

The embodiment ethylenic polymer may be used in a variety of films,including but not limited to clarity shrink films, collation shrinkfilms, cast stretch films, silage films, stretch hooder films, sealants,and diaper backsheets.

The embodiment ethylenic polymer is also useful in other direct end-useapplications. The embodiment ethylenic polymer is useful for wire andcable coating operations, in sheet extrusion for vacuum formingoperations, and forming molded articles, including the use of injectionmolding, blow molding process, or rotomolding processes. Compositionscomprising the embodiment ethylenic polymer can also be formed intofabricated articles using conventional polyolefin processing techniques.

Other suitable applications for the embodiment ethylenic polymer includeelastic films and fibers; soft touch goods, such as tooth brush handlesand appliance handles; gaskets and profiles; adhesives (including hotmelt adhesives and pressure sensitive adhesives); footwear (includingshoe soles and shoe liners); auto interior parts and profiles; foamgoods (both open and closed cell); impact modifiers for otherthermoplastic polymers such as high density polyethylene, isotacticpolypropylene, or other olefin polymers; coated fabrics; hoses; tubing;weather stripping; cap liners; flooring; and viscosity index modifiers,also known as pour point modifiers, for lubricants.

Further treatment of the embodiment ethylenic polymer may be performedto apply the embodiment ethylenic polymer for other end uses. Forexample, dispersions (both aqueous and non-aqueous) can also be formedusing the present polymers or formulations comprising the same. Frothedfoams comprising the embodiment ethylenic polymer can also be formed, asdisclosed in PCT Publication No. 2005/021622 (Strandeburg, et al.). Theembodiment ethylenic polymer may also be crosslinked by any known means,such as the use of peroxide, electron beam, silane, azide, or othercross-linking technique. The embodiment ethylenic polymer can also bechemically modified, such as by grafting (for example by use of maleicanhydride (MAH), silanes, or other grafting agent), halogenation,amination, sulfonation, or other chemical modification.

Additives and adjuvants may be added to the embodiment ethylenic polymerpost-formation. Suitable additives include fillers, such as organic orinorganic particles, including clays, talc, titanium dioxide, zeolites,powdered metals, organic or inorganic fibers, including carbon fibers,silicon nitride fibers, steel wire or mesh, and nylon or polyestercording, nano-sized particles, clays, and so forth; tackifiers, oilextenders, including paraffinic or napthelenic oils; and other naturaland synthetic polymers, including other polymers that are or can be madeaccording to the embodiment methods.

Blends and mixtures of the embodiment ethylenic polymer with otherpolyolefins may be performed. Suitable polymers for blending with theembodiment ethylenic polymer include thermoplastic and non-thermoplasticpolymers including natural and synthetic polymers. Exemplary polymersfor blending include polypropylene, (both impact modifyingpolypropylene, isotactic polypropylene, atactic polypropylene, andrandom ethylene/propylene copolymers), various types of polyethylene,including high pressure, free-radical LDPE, Ziegler-Natta LLDPE,metallocene PE, including multiple reactor PE (“in reactor” blends ofZiegler-Natta PE and metallocene PE, such as products disclosed in U.S.Pat. Nos. 6,545,088 (Kolthammer, et al.); 6,538,070 (Cardwell, et al.);6,566,446 (Parikh, et al.); 5,844,045 (Kolthammer, et al.); 5,869,575(Kolthammer, et al.); and 6,448,341 (Kolthammer, et al.)),ethylene-vinyl acetate (EVA), ethylene/vinyl alcohol copolymers,polystyrene, impact modified polystyrene, ABS, styrene/butadiene blockcopolymers and hydrogenated derivatives thereof (SBS and SEBS), andthermoplastic polyurethanes. Homogeneous polymers such as olefinplastomers and elastomers, ethylene and propylene-based copolymers (forexample, polymers available under the trade designation VERSIFY™Plastomers & Elastomers (The Dow Chemical Company) and VISTAMAXX™(ExxonMobil Chemical Co.)) can also be useful as components in blendscomprising the embodiment ethylenic polymer.

Blends and mixtures of the embodiment ethylenic polymer may includethermoplastic polyolefin blends (TPO), thermoplastic elastomer blends(TPE), thermoplastic vulcanizates (TPV) and styrenic polymer blends. TPEand TPV blends may be prepared by combining embodiment ethylenicpolymers, including functionalized or unsaturated derivatives thereof,with an optional rubber, including conventional block copolymers,especially an SBS block copolymer, and optionally a crosslinking orvulcanizing agent. TPO blends are generally prepared by blending theembodiment polymers with a polyolefin, and optionally a crosslinking orvulcanizing agent. The foregoing blends may be used in forming a moldedobject, and optionally crosslinking the resulting molded article. Asimilar procedure using different components has been previouslydisclosed in U.S. Pat. No. 6,797,779 (Ajbani, et al.).

Definitions

The term “composition,” as used, includes a mixture of materials whichcomprise the composition, as well as reaction products and decompositionproducts formed from the materials of the composition.

The terms “blend” or “polymer blend,” as used, mean an intimate physicalmixture (that is, without reaction) of two or more polymers. A blend mayor may not be miscible (not phase separated at molecular level). A blendmay or may not be phase separated. A blend may or may not contain one ormore domain configurations, as determined from transmission electronspectroscopy, light scattering, x-ray scattering, and other methodsknown in the art. The blend may be effected by physically mixing the twoor more polymers on the macro level (for example, melt blending resinsor compounding) or the micro level (for example, simultaneous formingwithin the same reactor).

The term “linear” refers to polymers where the polymer backbone of thepolymer lacks measurable or demonstrable long chain branches, forexample, the polymer is substituted with an average of less than 0.01long branch per 1000 carbons.

The term “polymer” refers to a polymeric compound prepared bypolymerizing monomers, whether of the same or a different type. Thegeneric term polymer thus embraces the term “homopolymer,” usuallyemployed to refer to polymers prepared from only one type of monomer,and the term “interpolymer” as defined. The terms “ethylene/α-olefinpolymer” is indicative of interpolymers as described.

The term “interpolymer” refers to polymers prepared by thepolymerization of at least two different types of monomers. The genericterm interpolymer includes copolymers, usually employed to refer topolymers prepared from two different monomers, and polymers preparedfrom more than two different types of monomers.

The term “ethylene-based polymer” refers to a polymer that contains morethan 50 mole percent polymerized ethylene monomer (based on the totalamount of polymerizable monomers) and, optionally, may contain at leastone comonomer.

The term “ethylene/α-olefin interpolymer” refers to an interpolymer thatcontains more than 50 mole percent polymerized ethylene monomer (basedon the total amount of polymerizable monomers) and at least oneα-olefin.

The term “ethylenic polymer” refers to a polymer resulting from thebonding of an ethylene-based polymer and at least one highly long chainbranched ethylene-based polymer.

Test Methods

Density

Samples that are measured for density are prepared according to ASTM D1928. Measurements are made within one hour of sample pressing usingASTM D792, Method B.

For some highly long chain branched ethylene-based polymers, density iscalculated (“calculated density”) in grams per cubic centimeter basedupon a relationship with the heat of fusion (H_(f)) in Joules per gramof the sample. The heat of fusion of the polymer sample is determinedusing the DSC Crystallinity method described infra.

To establish a relationship between density and heat of fusion forhighly branched ethylene based polymers, thirty commercially availableLDPE resins (designated “Commercially Available Resins” or “CAR”) aretested for density, melt index (I₂), heat of fusion, peak meltingtemperature, g′, gpcBR, and LCBf using the Density, Melt Index, DSCCrystallinity, Gel Permeation Chromatography, g′ by 3D-GPC, and gpcBRBranching Index by 3D-GPC methods, all described infra. The CommerciallyAvailable Resins have the properties listed in Table 1.

TABLE 1 Properties for several Commercially Available Resins.Commercially Melt Heat of Available Density Index (I₂) Fusion Peak gpcBRResins (g/cm³) (g/10 min) (J/g) T_(m) (° C.) Whole g′ avg MH LCBf CAR10.920 0.15 147.2 110.9 1.26 0.56 0.48 2.05 CAR2 0.922 2.5 151.1 111.40.89 0.62 0.49 2.03 CAR3 0.919 0.39 146.8 110.4 1.19 0.56 0.50 2.39 CAR40.922 0.80 155.0 112.5 0.78 0.61 0.50 1.99 CAR5 0.916 28 139.3 106.61.27 0.59 0.44 3.59 CAR6 0.917 6.4 141.5 107.8 1.48 0.56 0.45 3.24 CAR70.924 1.8 155.1 112.2 0.77 0.63 0.51 1.84 CAR8 0.926 5.6 157.9 113.40.57 0.67 0.54 1.64 CAR9 0.923 0.26 151.4 110.3 1.13 0.58 0.51 2.06CAR10 0.924 0.22 151.2 111.4 1.03 0.58 0.50 1.96 CAR11 0.924 0.81 154.1112.3 0.95 0.58 0.50 2.48 CAR12 0.926 5.9 158.0 113.1 0.70 0.66 0.501.90 CAR13 0.924 2.0 155.2 111.8 0.84 0.61 0.49 2.03 CAR14 0.923 4.1157.3 111.6 1.26 0.60 0.38 2.32 CAR15 0.922 33 153.5 111.8 0.46 0.690.27 1.95 CAR16 0.922 4.1 151.0 109.3 1.89 0.57 0.34 2.61 CAR17 0.9180.46 141.2 107.4 3.09 0.46 0.39 3.33 CAR18 0.921 2.1 145.9 110.2 0.850.60 0.41 2.11 CAR19 0.918 8.2 143.2 106.4 2.27 0.54 0.33 3.20 CAR200.922 0.67 148.7 110.4 0.68 0.62 0.42 1.59 CAR21 0.924 0.79 154.2 111.80.74 0.60 0.48 1.96 CAR22 0.922 0.25 150.0 110.5 0.92 0.57 0.47 1.92CAR23 0.924 3.4 153.6 111.3 0.65 0.63 0.48 1.94 CAR24 0.921 4.6 148.2106.9 1.49 0.58 0.36 2.54 CAR25 0.923 20 150.9 108.9 NM NM NM 2.21 CAR260.925 1.8 157.5 112.4 0.82 0.64 0.50 1.86 CAR27 0.923 0.81 153.7 111.50.87 0.62 0.50 1.94 CAR28 0.919 6.8 145.1 105.7 1.72 0.57 0.36 2.75CAR29 0.931 3.6 167.3 115.6 NM NM NM NM CAR30 0.931 2.3 169.3 115.8 NMNM NM NM Note that “NM” means not measured.

A graph showing the relationship between density and heat of fusion(H_(f)) for the Commercially Available Resins is shown in FIG. 2. R²given in FIG. 2 is the square of a correlation coefficient between theobserved and modeled data values. Based upon a linear regression, acalculated density, in grams per cubic centimeter, of commerciallyavailable highly long chain branched ethylene based polymers can bedetermined from the heat of fusion, in Joules per gram, using Equation1:

Calculated density=5.03E−04*(H _(f))+8.46E−01  (Eq. 1).

Melt Index

Melt index, or I₂, is measured in accordance with ASTM D 1238, Condition190° C./2.16 kg, and is reported in grams eluted per 10 minutes. I₁₀ ismeasured in accordance with ASTM D 1238, Condition 190° C./10 kg, and isreported in grams eluted per 10 minutes.

Brookfield Viscosity

Melt viscosity is determined using a Brookfield Laboratories(Middleboro, Mass.) DVII+ Viscometer and disposable aluminum samplechambers. The spindle used is a SC-31 hot-melt spindle suitable formeasuring viscosities from about 10 to about 100,000 centipoises. Otherspindles may be used to obtain viscosities if the viscosity of thepolymer is out of this range or in order to obtain the recommendedtorque ranges as described in this procedure. The sample is poured intothe sample chamber, inserted into a Brookfield Thermosel, and lockedinto place. The sample chamber has a notch on the bottom that fits thebottom of the Brookfield Thermosel to ensure that the chamber is notallowed to turn when the spindle is inserted and spinning The sample isheated to the required temperature (177° C.), until the melted sample isabout 1 inch (approximately 8 grams of resin) below the top of thesample chamber. The viscometer apparatus is lowered and the spindlesubmerged into the sample chamber. Lowering is continued until bracketson the viscometer align on the Thermosel. The viscometer is turned on,and set to operate at a shear rate which leads to a torque reading fromabout 30 to about 60 percent. Readings are taken every minute for about15 minutes or until the values stabilize, at which point, a finalreading is recorded.

DSC Crystallinity

Differential Scanning calorimetry (DSC) can be used to measure themelting and crystallization behavior of a polymer over a wide range oftemperature. For example, the TA Instruments Q1000 DSC, equipped with anRCS (refrigerated cooling system) and an autosampler is used to performthis analysis. During testing, a nitrogen purge gas flow of 50 ml/min isused. Each sample is melt pressed into a thin film at about 175° C.; themelted sample is then air-cooled to room temperature (˜25° C.). A 3-10mg, 6 mm diameter specimen is extracted from the cooled polymer,weighed, placed in a light aluminum pan (ca 50 mg), and crimped shut.Analysis is then performed to determine its thermal properties.

The thermal behavior of the sample is determined by ramping the sampletemperature up and down to create a heat flow versus temperatureprofile. First, the sample is rapidly heated to 180° C. and heldisothermal for 3 minutes in order to remove its thermal history. Next,the sample is cooled to −40° C. at a 10° C./minute cooling rate and heldisothermal at −40° C. for 3 minutes. The sample is then heated to 150°C. (this is the “second heat” ramp) at a 10° C./minute heating rate. Thecooling and second heating curves are recorded. The cool curve isanalyzed by setting baseline endpoints from the beginning ofcrystallization to −20° C. The heat curve is analyzed by settingbaseline endpoints from −20° C. to the end of melt. The valuesdetermined are peak melting temperature (T_(m)), peak crystallizationtemperature (T_(c)), heat of fusion (H_(f)) (in Joules per gram), andthe calculated % crystallinity for polyethylene samples using Equation2:

%Crystallinity=((H _(f))/(292 J/g))×100  (Eq. 2).

The heat of fusion (H_(f)) and the peak melting temperature are reportedfrom the second heat curve. Peak crystallization temperature isdetermined from the cooling curve.

Gel Permeation Chromatography (GPC)

The GPC system consists of a Waters (Milford, Mass.) 150 C hightemperature chromatograph (other suitable high temperatures GPCinstruments include Polymer Laboratories (Shropshire, UK) Model 210 andModel 220) equipped with an on-board differential refractometer (RI).Additional detectors can include an IR4 infra-red detector from PolymerChAR (Valencia, Spain), Precision Detectors (Amherst, Mass.) 2-anglelaser light scattering detector Model 2040, and a Viscotek (Houston,Tex.) 150R 4-capillary solution viscometer. A GPC with the last twoindependent detectors and at least one of the first detectors issometimes referred to as “3D-GPC”, while the term “GPC” alone generallyrefers to conventional GPC. Depending on the sample, either the15-degree angle or the 90-degree angle of the light scattering detectoris used for calculation purposes. Data collection is performed usingViscotek TriSEC software, Version 3, and a 4-channel Viscotek DataManager DM400. The system is also equipped with an on-line solventdegassing device from Polymer Laboratories (Shropshire, UK). Suitablehigh temperature GPC columns can be used such as four 30 cm long ShodexHT803 13 micron columns or four 30 cm Polymer Labs columns of 20-micronmixed-pore-size packing (MixA LS, Polymer Labs). The sample carouselcompartment is operated at 140° C. and the column compartment isoperated at 150° C. The samples are prepared at a concentration of 0.1grams of polymer in 50 milliliters of solvent. The chromatographicsolvent and the sample preparation solvent contain 200 ppm of butylatedhydroxytoluene (BHT). Both solvents are sparged with nitrogen. Thepolyethylene samples are gently stirred at 160° C. for four hours. Theinjection volume is 200 microliters. The flow rate through the GPC isset at 1 ml/minute.

The GPC column set is calibrated before running the Examples by runningtwenty-one narrow molecular weight distribution polystyrene standards.The molecular weight (MW) of the standards ranges from 580 to 8,400,000grams per mole, and the standards are contained in 6 “cocktail”mixtures. Each standard mixture has at least a decade of separationbetween individual molecular weights. The standard mixtures arepurchased from Polymer Laboratories (Shropshire, UK). The polystyrenestandards are prepared at 0.025 g in 50 mL of solvent for molecularweights equal to or greater than 1,000,000 grams per mole and 0.05 g in50 ml of solvent for molecular weights less than 1,000,000 grams permole. The polystyrene standards were dissolved at 80° C. with gentleagitation for 30 minutes. The narrow standards mixtures are run firstand in order of decreasing highest molecular weight component tominimize degradation. The polystyrene standard peak molecular weightsare converted to polyethylene M_(w) using the Mark-Houwink K and a(sometimes referred to as α) values mentioned later for polystyrene andpolyethylene. See the Examples section for a demonstration of thisprocedure.

With 3D-GPC absolute weight average molecular weight (“M_(w, Abs)”) andintrinsic viscosity are also obtained independently from suitable narrowpolyethylene standards using the same conditions mentioned previously.These narrow linear polyethylene standards may be obtained from PolymerLaboratories (Shropshire, UK; Part No.'s PL2650-0101 and PL2650-0102).

The systematic approach for the determination of multi-detector offsetsis performed in a manner consistent with that published by Balke,Mourey, et al. (Mourey and Balke, Chromatography Polym., Chapter 12,(1992)) (Balke, Thitiratsakul, Lew, Cheung, Mourey, ChromatographyPolym., Chapter 13, (1992)), optimizing triple detector log (M_(w) andintrinsic viscosity) results from Dow 1683 broad polystyrene (AmericanPolymer Standards Corp.; Mentor, Ohio) or its equivalent to the narrowstandard column calibration results from the narrow polystyrenestandards calibration curve. The molecular weight data, accounting fordetector volume off-set determination, are obtained in a mannerconsistent with that published by Zimm (Zimm, B. H., J. Chem. Phys., 16,1099 (1948)) and Kratochvil (Kratochvil, P., Classical Light Scatteringfrom Polymer Solutions, Elsevier, Oxford, N.Y. (1987)). The overallinjected concentration used in the determination of the molecular weightis obtained from the mass detector area and the mass detector constantderived from a suitable linear polyethylene homopolymer, or one of thepolyethylene standards. The calculated molecular weights are obtainedusing a light scattering constant derived from one or more of thepolyethylene standards mentioned and a refractive index concentrationcoefficient, dn/dc, of 0.104. Generally, the mass detector response andthe light scattering constant should be determined from a linearstandard with a molecular weight in excess of about 50,000 daltons. Theviscometer calibration can be accomplished using the methods describedby the manufacturer or alternatively by using the published values ofsuitable linear standards such as Standard Reference Materials (SRM)1475a, 1482a, 1483, or 1484a. The chromatographic concentrations areassumed low enough to eliminate addressing 2^(nd) viral coefficienteffects (concentration effects on molecular weight).

Analytical Temperature Rising Elution Fractionation (ATREF)

ATREF analysis is conducted according to the methods described in U.S.Pat. No. 4,798,081 (Hazlitt, et al.) and Wild, L.; Ryle, T. R.;Knobeloch, D. C.; Peat, I. R.; “Determination of Branching Distributionsin Polyethylene and Ethylene Copolymers”, J. Polym. Sci., 20, 441-55(1982). The configurations and equipment are described in Hazlitt, L.G., “Determination of Short-chain Branching Distributions of EthyleneCopolymers by Automated Temperature Rising Elution Fractionation(Auto-ATREF)”, Journal of Applied Polymer Science: Appl. Polym. Symp.,45, 25-39 (1990). The polymer sample is dissolved in TCB (0.2% to 0.5%by weight) at 120° C. to 140° C., loaded on the column at an equivalenttemperature, and allowed to crystallize in a column containing an inertsupport (stainless steel shot, glass beads, or a combination thereof) byslowly reducing the temperature to 20° C. at a cooling rate of 0.1°C./minute. The column is connected to an infrared detector (and,optionally, to a LALLS detector and viscometer) commercially availableas described in the Gel Permeation Chromatography Method section. AnATREF chromatogram curve is then generated by eluting the crystallizedpolymer sample from the column while increasing the temperature (1°C./minute) of the column and eluting solvent from 20 to 120° C. at arate of 1.0° C./minute.

Fast Temperature Rising Elution Fractionation (F-TREF)

The fast-TREF is performed with a Crystex instrument by Polymer ChAR(Valencia, Spain) in orthodichlorobenzene (ODCB) with IR-4 infrareddetector in compositional mode (Polymer ChAR, Spain) and lightscattering (LS) detector (Precision Detector Inc., Amherst, Mass.).

In F-TREF, 120 mg of the sample is added into a Crystex reactor vesselwith 40 ml of ODCB held at 160° C. for 60 minutes with mechanicalstirring to achieve sample dissolution. The sample is loaded onto TREFcolumn. The sample solution is then cooled down in two stages: (1) from160° C. to 100° C. at 40° C./minute, and (2) the polymer crystallizationprocess started from 100° C. to 30° C. at 0.4° C./minute. Next, thesample solution is held isothermally at 30° C. for 30 minutes. Thetemperature-rising elution process starts from 30° C. to 160° C. at 1.5°C./minute with flow rate of 0.6 ml/minute. The sample loading volume is0.8 ml. Sample molecular weight (M_(w)) is calculated as the ratio ofthe 15° or 90° LS signal over the signal from measuring sensor of IR-4detector. The LS-MW calibration constant is obtained by usingpolyethylene national bureau of standards SRM 1484a. The elutiontemperature is reported as the actual oven temperature. The tubing delayvolume between the TREF and detector is accounted for in the reportedTREF elution temperature.

Preparative Temperature Rising Elution Fractionation (P-TREF)

The temperature rising elution fractionation method (TREF) used topreparatively fractionate the polymers (P-TREF) is derived from Wilde,L.; Ryle, T. R.; Knobeloch, D. C.; Peat, I. R.; “Determination ofBranching Distributions in Polyethylene and Ethylene Copolymers”, J.Polym. Sci., 20, 441-455 (1982), including column dimensions, solvent,flow and temperature program. An infrared (IR) absorbance detector isused to monitor the elution of the polymer from the column. Separatetemperature programmed liquid baths—one for column loading and one forcolumn elution—are also used.

Samples are prepared by dissolution in trichlorobenzene (TCB) containingapproximately 0.5% 2,6-di-tert-butyl-4-methylphenol at 160° C. with amagnetic stir bar providing agitation. Sample load is approximately 150mg per column. After loading at 125° C., the column and sample arecooled to 25° C. over approximately 72 hours. The cooled sample andcolumn are then transferred to the second temperature programmable bathand equilibrated at 25° C. with a 4 ml/minute constant flow of TCB. Alinear temperature program is initiated to raise the temperatureapproximately 0.33° C./minute, achieving a maximum temperature of 102°C. in approximately 4 hours.

Fractions are collected manually by placing a collection bottle at theoutlet of the IR detector. Based upon earlier ATREF analysis, the firstfraction is collected from 56 to 60° C. Subsequent small fractions,called subfractions, are collected every 4° C. up to 92° C., and thenevery 2° C. up to 102° C. Subfractions are referred to by the midpointelution temperature at which the subfraction is collected.

Subfractions are often aggregated into larger fractions by ranges ofmidpoint temperature to perform testing. For the purposes of testingembodiment ethylenic polymers, subfractions with midpoint temperaturesin the range of 97 to 101° C. are combined together to give a fractioncalled “Fraction A”. Subfractions with midpoint temperatures in therange of 90 to 95° C. are combined together to give a fraction called“Fraction B”. Subfractions with midpoint temperatures in the range of 82to 86° C. are combined together to give a fraction called “Fraction C”.Subfractions with midpoint temperatures in the range of 62 to 78° C. arecombined together to give a fraction called “Fraction D”. Fractions maybe further combined into larger fractions for testing purposes.

A weight-average elution temperature is determined for each Fractionbased upon the average of the elution temperature range for eachsubfraction and the weight of the subfraction versus the total weight ofthe sample. Weight average temperature as determined by Equation 3 isdefined as:

$\begin{matrix}{{T_{W} = {\sum\limits_{T}\; {{T(f)}*{{A(f)}/{\sum\limits_{T}\; {A(f)}}}}}},} & \left( {{Eq}.\mspace{14mu} 3} \right)\end{matrix}$

where T(f) is the mid-point temperature of a narrow slice or segment andA(f) is the area of the segment, proportional to the amount of polymer,in the segment.

Data are stored digitally and processed using an EXCEL (Microsoft Corp.;Redmond, Wash.) spreadsheet. The TREF plot, peak maximum temperatures,fraction weight percentages, and fraction weight average temperatureswere calculated with the spreadsheet program.

Post P-TREF Polymer Fraction Preparation

Fractions A, B, C, and D are prepared for subsequent analysis by removalof trichlorobenzene (TCB). This is a multi-step process in which onepart TCB solution is combined with three parts methanol. Theprecipitated polymer for each fraction is filtered onto fluoropolymermembranes, washed with methanol, and air dried. The polymer-containingfilters are then placed in individual vials with enough xylene to coverthe filter. The vials are heated to 135° C., at which point the polymereither dissolves in the xylene or is lifted from the filter as plates orflakes. The vials are cooled, the filters are removed, and the xylene isevaporated under a flowing nitrogen atmosphere at room temperature. Thevials are then placed in a vacuum oven, the pressure reduced to −28inches Hg, and the temperature raised to 80° C. for two hours to removeresidual xylene. The four Fractions are analyzed using IR spectroscopyand gel permeation chromatography to obtain a number average molecularweight. For IR analysis, Fractions may have to be combined into largerfractions to obtain a high enough signal to noise in the IR spectra.

Methyls Per 1000 Carbons Determination on P-TREF Fractions

The analysis follows Method B in ASTM D-2238 except for slight deviationin the procedure to account for smaller-than-standard sample sizes, asdescribed in this procedure. In the ASTM procedure polyethylene filmsapproximately 0.25 mm thick are scanned by infrared and analyzed. Theprocedure described is modified to permit similar testing using smalleramounts of material generated by the P-TREF separation.

For each of the Fractions, a piece of polymer is pressed betweenaluminum foil in a heated hydraulic press to create a film approximately4 mm in diameter and 0.02 mm thick. The film is then placed on a NaCldisc 13 mm in diameter and 2 mm thick and scanned by infrared using anIR microscope. The FTIR spectrometer is a Thermo Nicolet Nexus 470 witha Continuum microscope equipped with a liquid nitrogen cooled MCTdetector. One hundred twenty eight scans are collected at 2 wavenumberresolution using 1 level of 0 filling.

The methyls are measured using the 1378 cm⁻¹ peak. The calibration usedis the same calibration derived by using ASTM D-2238. The FTIR isequipped with Thermo Nicolet Omnic software.

The uncorrected methyls per 1000 carbons, X, are corrected for chainends using their corresponding number average molecular weight, M_(n),to obtain corrected methyls per thousand, Y, as shown in Equation 4:

Y=X−21,000/M _(n)  (Eq. 4).

The value of 21,000 is used to allow for the lack of reliable signal toobtain unsaturation levels in the sub-fractions. In general, though,these corrections are small (<0.4 methyls per 1000 carbons).

g′ by 3D-GPC

The index (g′) for the sample polymer is determined by first calibratingthe light scattering, viscosity, and concentration detectors describedin the Gel Permeation Chromatography method supra with SRM 1475ahomopolymer polyethylene (or an equivalent reference). The lightscattering and viscometer detector offsets are determined relative tothe concentration detector as described in the calibration. Baselinesare subtracted from the light scattering, viscometer, and concentrationchromatograms and integration windows are then set making certain tointegrate all of the low molecular weight retention volume range in thelight scattering and viscometer chromatograms that indicate the presenceof detectable polymer from the refractive index chromatogram. A linearhomopolymer polyethylene is used to establish a Mark-Houwink (MH) linearreference line by injecting a broad molecular weight polyethylenereference such as SRM1475a standard, calculating the data file, andrecording the intrinsic viscosity (IV) and molecular weight (M_(w)),each derived from the light scattering and viscosity detectorsrespectively and the concentration as determined from the RI detectormass constant for each chromatographic slice. For the analysis ofsamples the procedure for each chromatographic slice is repeated toobtain a sample Mark-Houwink line. Note that for some samples the lowermolecular weights, the intrinsic viscosity and the molecular weight datamay need to be extrapolated such that the measured molecular weight andintrinsic viscosity asymptotically approach a linear homopolymer GPCcalibration curve. To this end, many highly-branched ethylene-basedpolymer samples require that the linear reference line be shiftedslightly to account for the contribution of short chain branching beforeproceeding with the long chain branching index (g′) calculation.

A g-prime (g_(i)′) is calculated for each branched samplechromatographic slice (i) and measuring molecular weight (M_(i))according to Equation 5:

g _(i)′=(IV _(sample,i) /IV _(linear reference,j))  (Eq. 5),

where the calculation utilizes the IV_(linear reference,j) at equivalentmolecular weight, M_(j), in the linear reference sample. In other words,the sample IV slice (i) and reference IV slice (j) have the samemolecular weight (M_(i)=M_(j)). For simplicity, theIV_(linear reference,j) slices are calculated from a fifth-orderpolynomial fit of the reference Mark-Houwink Plot. The IV ratio, org_(i)′, is only obtained at molecular weights greater than 3,500 becauseof signal-to-noise limitations in the light scattering data. The numberof branches along the sample polymer (B_(n)) at each data slice (i) canbe determined by using Equation 6, assuming a viscosity shieldingepsilon factor of 0.75:

$\begin{matrix}{\left\lbrack \frac{{IV}_{{Sample},i}}{{IV}_{{linear\_ reference},j}} \right\rbrack_{M_{i = j}}^{1.33} = {\left\lbrack {\left( {1 + \frac{B_{n,i}}{7}} \right)^{1/2} + {\frac{4}{9}\frac{B_{n,i}}{\pi}}} \right\rbrack^{{- 1}/2}.}} & \left( {{Eq}.\mspace{14mu} 6} \right)\end{matrix}$

Finally, the average LCBf quantity per 1000 carbons in the polymeracross all of the slices (i) can be determined using Equation 7:

$\begin{matrix}{{LCBf} = {\frac{\sum\limits_{M = 3500}^{i}\; \left( {\frac{B_{n,i}}{M_{i}/14000}c_{i}} \right)}{\sum\; c_{i}}.}} & \left( {{Eq}.\mspace{14mu} 7} \right)\end{matrix}$

gpcBR Branching Index by 3D-GPC

In the 3D-GPC configuration the polyethylene and polystyrene standardscan be used to measure the Mark-Houwink constants, K and α,independently for each of the two polymer types, polystyrene andpolyethylene. These can be used to refine the Williams and Wardpolyethylene equivalent molecular weights in application of thefollowing methods.

The gpcBR branching index is determined by first calibrating the lightscattering, viscosity, and concentration detectors as describedpreviously. Baselines are then subtracted from the light scattering,viscometer, and concentration chromatograms. Integration windows arethen set to ensure integration of all of the low molecular weightretention volume range in the light scattering and viscometerchromatograms that indicate the presence of detectable polymer from therefractive index chromatogram. Linear polyethylene standards are thenused to establish polyethylene and polystyrene Mark-Houwink constants asdescribed previously. Upon obtaining the constants, the two values areused to construct two linear reference conventional calibrations (“cc”)for polyethylene molecular weight and polyethylene intrinsic viscosityas a function of elution volume, as shown in Equations 8 and 9:

$\begin{matrix}{{M_{PE} = {\left( \frac{K_{PS}}{K_{PE}} \right)^{{1/\alpha_{PE}} + 1} \cdot M_{PS}^{\alpha_{PS} + {1/\alpha_{PE}} + 1}}},{and}} & \left( {{Eq}.\mspace{14mu} 8} \right) \\{\lbrack\eta\rbrack_{PE} = {K_{PS} \cdot {M_{PS}^{\alpha + 1}/{M_{PE}.}}}} & \left( {{Eq}.\mspace{14mu} 9} \right)\end{matrix}$

The gpcBR branching index is a robust method for the characterization oflong chain branching. See Yau, Wallace W., “Examples of Using3D-GPC—TREF for Polyolefin Characterization”, Macromol. Symp., 2007,257, 29-45. The index avoids the slice-by-slice 3D-GPC calculationstraditionally used in the determination of g′ values and branchingfrequency calculations in favor of whole polymer detector areas and areadot products. From 3D-GPC data, one can obtain the sample bulk M_(w) bythe light scattering (LS) detector using the peak area method. Themethod avoids the slice-by-slice ratio of light scattering detectorsignal over the concentration detector signal as required in the g′determination.

$\begin{matrix}{M_{W} = {{\sum\limits_{i}\; {w_{i}M_{i}}} = {{\sum\limits_{i}\; {\left( \frac{C_{i}}{\sum\limits_{i}\; C_{i}} \right)M_{i}}} = {\frac{\sum\limits_{i}\; {C_{i}M_{i}}}{\sum\limits_{i}\; C_{i}} = {\frac{\sum\limits_{i}\; {LS}_{i}}{\sum\limits_{i}\; C_{i}} = {\frac{{LS}\mspace{14mu} {Area}}{{Conc}.\mspace{14mu} {Area}}.}}}}}} & \left( {{Eq}.\mspace{14mu} 10} \right)\end{matrix}$

The area calculation in Equation 10 offers more precision because as anoverall sample area it is much less sensitive to variation caused bydetector noise and GPC settings on baseline and integration limits. Moreimportantly, the peak area calculation is not affected by the detectorvolume offsets. Similarly, the high-precision sample intrinsic viscosity(IV) is obtained by the area method shown in Equation 11:

$\begin{matrix}{{{IV} = {\lbrack\eta\rbrack = {{\sum\limits_{i}\; {w_{i}{IV}_{i}}} = {{\sum\limits_{i}\; {\left( \frac{C_{i}}{\sum\limits_{i}\; C_{i}} \right){IV}_{i}}} = {\frac{\sum\limits_{i}\; {C_{i}{IV}_{i}}}{\sum\limits_{i}\; C_{i}} = {\frac{\sum\limits_{i}\; {DP}_{i}}{\sum\limits_{i}\; C_{i}} = \frac{{DP}\mspace{14mu} {Area}}{{Conc}.\mspace{14mu} {Area}}}}}}}},} & \left( {{Eq}.\mspace{14mu} 11} \right)\end{matrix}$

where DP_(i) stands for the differential pressure signal monitoreddirectly from the online viscometer.

To determine the gpcBR branching index, the light scattering elutionarea for the sample polymer is used to determine the molecular weight ofthe sample. The viscosity detector elution area for the sample polymeris used to determine the intrinsic viscosity (IV or [η]) of the sample.

Initially, the molecular weight and intrinsic viscosity for a linearpolyethylene standard sample, such as SRM1475a or an equivalent, aredetermined using the conventional calibrations for both molecular weightand intrinsic viscosity as a function of elution volume, per Equations12 and 13:

$\begin{matrix}{{{Mw}_{CC} = {{\sum\limits_{i}\; {\left( \frac{C_{i}}{\sum\limits_{i}\; C_{i}} \right)M_{i}}} = {\sum\limits_{i}\; {w_{i}M_{i}}}}},{and}} & \left( {{Eq}.\mspace{14mu} 12} \right) \\{\lbrack\eta\rbrack_{CC} = {{\sum\limits_{i}\; {\left( \frac{C_{i}}{\sum\limits_{i}\; C_{i}} \right){IV}_{i}}} = {\sum\limits_{i}\; {w_{i}{{IV}_{i}.}}}}} & \left( {{Eq}.\mspace{14mu} 13} \right)\end{matrix}$

Equation 14 is used to determine the gpcBR branching index:

$\begin{matrix}{{{gpcBR} = \left\lbrack {{\left( \frac{\lbrack\eta\rbrack_{CC}}{\lbrack\eta\rbrack} \right) \cdot \left( \frac{M_{W}}{M_{W,{CC}}} \right)^{\alpha_{PE}}} - 1} \right\rbrack},} & \left( {{Eq}.\mspace{14mu} 14} \right)\end{matrix}$

where [η] is the measured intrinsic viscosity, [η]_(cc) is the intrinsicviscosity from the conventional calibration, M_(w) is the measuredweight average molecular weight, and M_(w,cc) is the weight averagemolecular weight of the conventional calibration. The Mw by lightscattering (LS) using Equation (10) is commonly referred to as theabsolute Mw; while the Mw,cc from Equation (12) using the conventionalGPC molecular weight calibration curve is often referred to as polymerchain Mw. All statistical values with the “cc” subscript are determinedusing their respective elution volumes, the corresponding conventionalcalibration as previously described, and the concentration (C_(i))derived from the mass detector response. The non-subscripted values aremeasured values based on the mass detector, LALLS, and viscometer areas.The value of K_(PE) is adjusted iteratively until the linear referencesample has a gpcBR measured value of zero. For example, the final valuesfor α and Log K for the determination of gpcBR in this particular caseare 0.725 and −3.355, respectively, for polyethylene, and 0.722 and−3.993 for polystyrene, respectively.

Once the K and α values have been determined, the procedure is repeatedusing the branched samples. The branched samples are analyzed using thefinal Mark-Houwink constants as the best “cc” calibration values andapplying Equations 10-14.

The interpretation of gpcBR is straight forward. For linear polymers,gpcBR calculated from Equation 14 will be close to zero since the valuesmeasured by LS and viscometry will be close to the conventionalcalibration standard. For branched polymers, gpcBR will be higher thanzero, especially with high levels of LCB, because the measured polymerM_(w) will be higher than the calculated M_(w,cc), and the calculatedIV_(cc) will be higher than the measured polymer IV. In fact, the gpcBRvalue represents the fractional IV change due the molecular sizecontraction effect as the result of polymer branching. A gpcBR value of0.5 or 2.0 would mean a molecular size contraction effect of IV at thelevel of 50% and 200%, respectively, versus a linear polymer molecule ofequivalent weight.

For these particular Examples, the advantage of using gpcBR incomparison to the g′ index and branching frequency calculations is dueto the higher precision of gpcBR. All of the parameters used in thegpcBR index determination are obtained with good precision and are notdetrimentally affected by the low 3D-GPC detector response at highmolecular weight from the concentration detector. Errors in detectorvolume alignment also do not affect the precision of the gpcBR indexdetermination. In other particular cases, other methods for determiningM_(w) moments may be preferable to the aforementioned technique.

Nuclear Magnetic Resonance (¹³C NMR)

Samples involving LDPE and the inventive examples are prepared by addingapproximately 3 g of a 50/50 mixture oftetrachloroethane-d₂/orthodichlorobenzene containing 0.025 M Cr(AcAc)₃to a 0.25 g polymer sample in a 10 mm NMR tube. Oxygen is removed fromthe sample by placing the open tubes in a nitrogen environment for atleast 45 minutes. The samples are then dissolved and homogenized byheating the tube and its contents to 150° C. using a heating block andheat gun. Each dissolved sample is visually inspected to ensurehomogeneity. Samples are thoroughly mixed immediately prior to analysisand were not allowed to cool before insertion into the heated NMR sampleholders.

The ethylene-based polymer samples are prepared by adding approximately3 g of a 50/50 mixture of tetrachloroethane-d₂/orthodichlorobenzenecontaining 0.025 M Cr(AcAc)₃ to 0.4 g polymer sample in a 10 mm NMRtube. Oxygen is removed from the sample by placing the open tubes in anitrogen environment for at least 45 minutes. The samples are thendissolved and homogenized by heating the tube and its contents to 150°C. using a heating block and heat gun. Each dissolved sample is visuallyinspected to ensure homogeneity. Samples are thoroughly mixedimmediately prior to analysis and are not allowed to cool beforeinsertion into the heated NMR sample holders.

All data are collected using a Bruker 400 MHz spectrometer. The data isacquired using a 6 second pulse repetition delay, 90-degree flip angles,and inverse gated decoupling with a sample temperature of 125° C. Allmeasurements are made on non-spinning samples in locked mode. Samplesare allowed to thermally equilibrate for 15 minutes prior to dataacquisition. The ¹³C NMR chemical shifts were internally referenced tothe EEE triad at 30.0 ppm.

C13 NMR Comonomer Content

It is well known to use NMR spectroscopic methods for determiningpolymer composition. ASTM D 5017-96, J. C. Randall et al., in “NMR andMacromolecules” ACS Symposium series 247, J. C. Randall, Ed., Am. Chem.Soc., Washington, D.C., 1984, Ch. 9, and J. C. Randall in “PolymerSequence Determination”, Academic Press, New York (1977) provide generalmethods of polymer analysis by NMR spectroscopy.

Cross-Fractionation by TREF (xTREF)

The cross-fractionation by TREF (xTREF) provides a separation by bothmolecular weight and crystallinity using ATREF and GPC. Nakano and Goto,J. Appl. Polym. Sci., 24, 4217-31 (1981), described the firstdevelopment of an automatic cross fractionation instrument. The typicalxTREF process involves the slow crystallization of a polymer sample ontoan ATREF column (composed of glass beads and steel shot). After theATREF step of crystallization the polymer is sequentially eluted inpredetermined temperature ranges from the ATREF column and the separatedpolymer fractions are measured by GPC. The combination of the elutiontemperature profile and the individual GPC profiles allow for a3-dimensional representation of a more complete polymer structure(weight distribution of polymer as function of molecular weight andcrystallinity). Since the elution temperature is a good indicator forthe presence of short chain branching, the method provides a fairlycomplete structural description of the polymer.

A detailed description of the design and operation of thecross-fractionation instrument can be found in PCT Publication No. WO2006/081116 (Gillespie, et al.). FIG. 12 shows a schematic for the xTREFinstrument 500. This instrument has a combination of at least one ATREFoven 600 and a GPC 700. In this method, a Waters GPC 150 is used. ThexTREF instrument 500, through a series of valve movements, operates by(1) injecting solutions into a sample loop and then to the ATREF column,(2) crystallizing the polymer by cooling the ATREF oven/column, and (3)eluting the fractions in step-wise temperature increments into the GPC.Heated transfer lines 505, kept at approximately 150° C., are used foreffluent flow between various components of the xTREF instrument 500.Five independent valve systems (GPC 700 2-way/6-port valve 750 and2-way/3-port valve 760; ATREF oven 600 valves 650, 660, and 670) controlthe flow path of the sample.

The refractive index (RI) GPC detector 720 is quite sensitive to solventflow and temperature. Fluctuations in the solvent pressure duringcrystallization and elution can lead to elution artifacts during theTREF elution. An external infrared (IR) detector 710, the IR4, suppliedby Polymer ChAR (Valencia, Spain) is added as the primary concentrationdetector (RI detector 720) to alleviate this concern. Other detectors(not shown) are the LALLS and viscometer configured as described in theGel Permeation Chromatography method, provided infra in the TestingMethods section. In FIG. 12, a 2-way/6-port valve 750 and a 2-way/3-portvalve 760 (Valco; Houston, Tex.) are placed in the Waters 150 C heatedcolumn compartment 705.

Each ATREF oven 600 (Gaumer Corporation, Houston, Tex.) uses a forcedflow gas (nitrogen) design and are well insulated. Each ATREF column 610is constructed of 316 SS 0.125″ OD by 0.105″ (3.18 millimeter) IDprecision bore tubing. The tubing is cut to 19.5″ (495.3 millimeters)length and filled with a 60/40 (v/v) mix of stainless steel 0.028″ (0.7millimeter) diameter cut wire shot and 30-40 mesh spherical technicalquality glass. The stainless steel cut wire shot is from Pellets, Inc.(North Tonawanda, N.Y.). The glass spheres are from Potters Industries(Brownwood, Tex.). The interstitial volume was approximately 1.00 ml.Parker fitted low internal volume column end fittings (Part number 2-1Z2HCZ-4-SS) are placed on each tube end and the tubing is wrapped into a1.5″ (38.1 millimeters) coil. Since TCB has a very high heat capacity ata standard flowrate of 1.0 ml/minute, the ATREF column 610 (which has aninterstitial volume of around 1 ml) may be heated or quenched withoutthe pre-equilibration coil 605. It should be noted that thepre-equilibration coil 605 has a large volume (>12 milliliters) and,therefore, is only inline during the ATREF elution cycle (and not theATREF loading cycle). The nitrogen to the ATREF oven 600 passed througha thermostatically controlled chiller (Airdyne; Houston, Tex.) with a100 psig nitrogen supply capable of discharging 100 scf/minute of 5 to8° C. nitrogen. The chilled nitrogen is piped to each analytical ovenfor improved low temperature control purposes.

The polyethylene samples are prepared in 2-4 mg/ml TCB depending uponthe distribution, density, and the desired number of fractions to becollected. The samples preparation is similar to that of conventionalGPC.

The system flow rate is controlled at 1 ml/minute for both the GPCelution and the ATREF elution using the GPC pump 740 and GPC sampleinjector 745. The GPC separation is accomplished through four 10 μm“Mixed B” linear mixed bed GPC columns 730 supplied by PolymerLaboratories (UK). The GPC heated column compartment 705 is operated at145° C. to prevent precipitation when eluting from the ATREF column 610.Sample injection amount is 500 μl. The ATREF oven 600 conditions are:temperature is from about 30 to about 110° C.; crystallization rate ofabout 0.123° C./minute during a 10.75 hour period; an elution rate of0.123° C./minute during a 10.75 hour period; and 14 P-TREF fractions.

The GPC 700 is calibrated in the same way as for conventional GPC exceptthat there is “dead volume” contained in the cross-fractionation systemdue to the ATREF column 610. Providing a constant volume offset to thecollected GPC data from a given ATREF column 610 is easily implementedusing the fixed time interval that is used while the ATREF column 620 isbeing loaded from the GPC sample injector 745 and converting that(through the flow rate) to an elution volume equivalent. The offset isnecessary because during the operation of the instrument, the GPC starttime is determined by the valve at the exit end of the ATREF column andnot the GPC injector system. The presence of the ATREF column 610 alsocauses some small reduction in apparent GPC column 730 efficiency.Careful construction of the ATREF columns 610 will minimize its effecton GPC column 730 performance.

During a typical analysis, 14 individual ATREF fractions are measured byGPC. Each ATREF fraction represents approximately a 5-7° C.-temperature“slice”. The molecular weight distribution (MWD) of each slice iscalculated from the integrated GPC chromatograms. A plot of the GPC MWDsas a function of temperature (resulting in a 3D surface plot) depictsthe overall molecular weight and crystallinity distribution. In order tocreate a smoother 3D surface, the 14 fractions are interpolated toexpand the surface plot to include 40 individual GPC chromatograms aspart of the calculation process. The area of the individual GPCchromatograms correspond to the amount eluted from the ATREF fraction(across the 5-7° C.-temperature slice). The individual heights of GPCchromatograms (Z-axis on the 3D plot) correspond to the polymer weightfraction thus giving a representation of the proportion of polymerpresent at that level of molecular weight and crystallinity.

EXAMPLES Preparation of Ethylene-Based Polymers

A continuous solution polymerization is carried out in acomputer-controlled well mixed reactor to form three ethylene-basedpolyethylene polymers. The solvent is a purified mixed alkanes solventcalled ISOPAR E (ExxonMobil Chemical Co., Houston, Tex.). A feed ofethylene, hydrogen, and polymerization catalyst are fed into a 39 gallon(0.15 cubic meters) reactor. See Table 2 for the amounts of feed andreactor conditions for the formation of each of the three ethylene-basedpolyethylene polymers, designated Polymer (P) 1-3. “SCCM” in Table 2 isstandard cubic centimeters per minute gas flow. The catalyst for allthree of the ethylene-based polyethylene polymers is a titanium-basedconstrained geometry catalyst (CGC) with the composition Titanium,[N-(1,1-dimethylethyl)-1,1-dimethyl-1-[(1,2,3,3a,7a-η)-3-(1-pyrrolidinyl)-1H-inden-1-yl]silanaminato(2-)κN][(1,2,3,4-η)-1,3-pentadiene].The cocatalyst is a modified methylalumoxane (MMAO). The CGC activatoris a blend of amines, bis(hydrogenated tallow alkyl)methyl, andtetrakis(pentafluorophenyl)borate(1-). The reactor is run liquid-full atapproximately 525 psig.

The process of polymerization is similar to the procedure detailed inExamples 1-4 and FIG. 1 of U.S. Pat. No. 5,272,236 (Lai, et al.) andExample 1 of U.S. Pat. No. 5,278,272 (Lai, et al.), except that acomonomer is not used in forming P 1-3. Because no comonomer is used, P1-3 are ethylene homopolymers. Conversion is measured as percentethylene conversion in the reactor. Efficiency is measured as the weightof the polymer in kilograms produced by grams of titanium in thecatalyst.

After emptying the reactor, additives (1300 ppm IRGAFOS 168, 200 ppmIRGANOX 1010, 250 ppm IRGANOX 1076, 1250 ppm calcium stearate) areinjected into each of the three ethylene-based polyethylene polymerpost-reactor solutions. Each post-reactor solution is then heated inpreparation for a two-stage devolatization. The solvent and unreactedmonomers are removed from the post-reactor solution during thedevolatization process. The resultant polymer melt is pumped to a diefor underwater pellet cutting.

Selected properties for P1-3 are provided in Table 3. P1-3 are presentedwith density, melt index (I₂), I₁₀, and Brookfield viscosity determinedusing the Density, Melt Index, and Brookfield Viscosity methods, alldescribed infra. “NM” means not measured.

TABLE 2 Feed amounts and reactor conditions for creating ethylene-basedpolymers P1-3. C₂H₄ Solvent Catalyst Activator Activator Polymer FeedFeed H₂ T Catalyst Flow Conc. Flow Samples (kg/hr) (kg/hr) (sccm) (° C.)(ppm) (kg/hr) (ppm) (kg/hr) P1 178 1,261 19,067 160 84 0.5897 3,4620.5012 P2 144 1,021 25,581 157 441 0.6020 5,572 1.783 P3 177 1,260 8,998150 84 0.3777 3,462 0.3187 Cocatalyst Cocatalyst Polymerization PolymerConc. Flow Rate Conversion Solids Samples (ppm) (kg/hr) (kg/hr) (%) %Efficiency P1 311 0.7160 160 85.3 11.1 3,239 P2 699 0.8553 139 90.4 11.9522 P3 291 0.4917 157 84.1 10.9 4,956

TABLE 3 Selected properties for ethylene-based polymers P1-3. BrookfieldPolymer Density Viscosity (cP) Samples (g/cm³) I₂ I₁₀ I₁₀/I₂ 177° C. P10.965 62   387 6.2 NM P2 0.967 NM NM NM 10,818 P3 0.958 4.9  29 5.8 NM

Preparation of Example Ethylenic Polymers 1 and 2 Example 1

Two grams of Polymer 2 (P2) are added to a 100 ml autoclave reactor.After closing the reactor, the agitator is turned on at 1000 rpm(revolutions per minute). The reactor is deoxygenated by pulling vacuumon the system and pressurizing with nitrogen. This is repeated threetimes. The reactor is then pressurized with ethylene up to 2000 barwhile at ambient temperatures and then vented off. This is repeatedthree times. On the final ethylene vent of the reactor, the pressure isdropped only to a pressure of about 100 bar, where the reactor heatingcycle is initiated. Upon achieving an internal temperature of ˜220° C.,the reactor is then pressurized with ethylene to about 1600 bar and heldat 220° C. for at least 30 minutes. The estimated amount of ethylene inthe reactor is approximately 46.96 grams. Ethylene is then used to sweep3.0 ml of a mixture of 0.5648 mmol/ml propionaldehyde and 0.01116mmol/ml tert-butyl peroxyacetate initiator in n-heptane into thereactor. An increase in pressure (to ˜2000 bar) in conjunction with theaddition of initiator causes the ethylene monomer to free-radicalpolymerize. The polymerization leads to a temperature increase to 274°C. After allowing the reactor to continue to mix for 15 minutes, thereactor is depressurized, purged, and opened. A total of 4.9 grams ofresultant ethylenic polymer, designated Example 1, is physicallyrecovered from the reactor (some additional product polymer isunrecoverable due to the reactor bottom exit plugging). Based upon theconversion value of ethylene in the reactor, the ethylenic polymer ofExample 1 comprises up to 40 weight percent ethylene-based polyethyleneP2 and the balance is highly long chain branched ethylene-based polymergenerated by free-radical polymerization.

Comparative Example 1

Free-radical polymerization of ethylene under the same processconditions as Example 1 without the addition of an ethylene-basedpolymer yields 4.9 grams of a highly long chain branched ethylene-basedpolymer designated as Comparative Example 1 (CE1). A temperatureincrease to 285° C. occurs during the reaction.

Example 2

Two grams of Polymer 1 (P1) are added to a 100 ml autoclave reactor.After closing the reactor, the agitator is turned on at 1000 rpm. Thereactor is deoxygenated by pulling vacuum on the system and pressurizingwith nitrogen. This is repeated three times. The reactor is thenpressurized with ethylene up to 2000 bar while at ambient temperaturesand then vented off. This is repeated three times. On the final ethylenevent of the reactor, the pressure is dropped only to a pressure of about100 bar, where the reactor heating cycle is initiated. Upon achieving aninternal temperature of ˜220° C., the reactor is then pressurized withethylene to about 1600 bar and held at 220° C. for at least 30 minutes.At this point the estimated amount of ethylene in the reactor isapproximately 46.96 grams. Ethylene is then used to sweep 3.0 ml of amixture of 0.5648 mmol/ml propionaldehyde and 0.01116 mmol/ml tert-butylperoxyacetate initiator in n-heptane into the reactor. The increase inpressure (to ˜2000 bar) in conjunction with the addition of initiatorcauses the ethylene to free-radical polymerize. The polymerization leadsto a temperature increase to 267° C. After allowing the reactor tocontinue to mix for 15 minutes, the reactor is depressurized, purged,and opened. A total of 7.4 grams of resultant ethylenic polymer,designated Example 2, is physically recovered from the reactor (someadditional product polymer is unrecoverable due to the reactor bottomexit plugging). Based upon the conversion value of ethylene in thereactor, ethylenic polymer of Example 2 comprises approximately 27weight percent ethylene-based polyethylene P1 and the balance is highlylong chain branched ethylene-based polymer generated by free-radicalpolymerization.

Characterization of Example Ethylenic Polymers 1 and 2

Both ethylenic polymers Examples 1 and 2, highly long chain branchedethylene-based polymer Comparative Example 1, and both ethylene-basedpolymers P1 and P2 are tested using the DSC Crystallinity method,provided infra in the Testing Methods section. The calculated densityfor the Comparative Example polymer are from the use of the Densitymethod, provided infra in the Testing Methods section. Results of thetesting are provided in Table 4 and FIGS. 3 and 4.

TABLE 4 Results of DSC Crystallinity testing for Examples 1 and 2,Comparative Example 1, and P1 and P2. Heat of High Melting Low MeltingCalculated fusion % Point Peak T_(m) Point Peak T_(m) Peak T_(c) DensityDensity Sample ID (J/g) Crystallinity (° C.) (° C.) (° C.) (g/cm³)(g/cm³) Example 1 156.3 53.5 116.6 111.5 106.0 0.937** NM P2 231.7 79.3130.0 NM 117.7 NM 0.967 Example 2 161.1 55.2 121.0 NM 109.1 0.930** NMP1 233.4 79.9 133.5 NM 116.6 NM 0.965 CE1 142.9 48.9 110.2 NM 96.60.918*  NM Note that “NM” designates not measured. Density is taken fromthe results of Table 3 for P1 and P2. *Calculated using equation 1.**Calculated using (1/ρ) = ((w₁/ρ₁) + (w₂/ρ₂)) where ρ = density of theexample (g/cm³) and w₁ = weight fraction of CE1 described in Preparationof Example Ethylenic Polymers 1 and 2 for that example and ρ₁ =calculated density for CE1 from equation 1 and w₂ = weight fractiondescribed in Preparation of Example Ethylenic Polymers 1 and 2 of eitherP1 or P2 used for that example and ρ₂ = measured density for either P1or P2 used for that example.

Both ethylenic polymer Examples 1 and 2 have peak melting temperaturevalues between that of Comparative Example 1, which is highly long chainbranched ethylene-based polymer made under the same base conditions asExamples 1 and 2, and each of their respective ethylene-basedpolyethylene Polymers 2 and 1. Table 4 shows the highest peak meltingtemperatures, T_(m), of the Examples are higher by about 7 to 11° C. andhave a greater amount of crystallinity, about 5 to 6 percent, versusComparative Example 1. Additionally, the peak crystallizationtemperatures, T_(e), are about 9 to 12° C. higher than ComparativeExample 1, indicating additional benefits in terms of the ability tocool or solidify at a higher temperature than CE1. The DSC Crystallinityresults indicate that the ethylenic polymer Examples 1 and 2 have bothhigher peak melting temperatures and peak crystallization temperaturesas well as different heats of fusion values than the comparative examplehighly long chain branched ethylene-based polymer (Comparative Example1). Additionally, Examples 1 and 2 also differ in some properties fromP2 and P1, especially the heat of fusion value. This strongly indicatesthat Examples 1 and 2 are different from their respective highly longchain branched ethylene-based polymer and ethylene-based polymercomponents.

FIGS. 3 and 4 show the heat flow versus temperature plots for theethylenic polymer Examples. Also shown in these figures are the heatflow versus temperature plots for the respective ethylene-basedpolyethylene P2 and P1 and Comparative Example 1.

Examples 1 and 2, Comparative Example 1, Polymer 1, and an 80:20 weightratio physical blend of CE1 and P1 are tested using the AnalyticalTemperature Rising Elution Fractionation method, provided infra in theTesting Methods section. In FIG. 5, the ATREF runs for Example 1 andComparative Example 1 are plotted. In FIG. 6, the ATREF runs for Example2, Polymer 1, Comparative Example 1, and an 80:20 weight ratio physicalblend of CE1 and P1 are plotted. Table 5 gives the percentage of totalweight fraction of each polymer sample eluting above 90° C.

TABLE 5 Weight percentage of total polymer eluting above 90° C. perATREF analysis. % Weight Fraction Sample ID Above 90° C. Example 1 19.0Comparative Example 1 0.0 Example 2 5.3 Physical Blend 80:20 CE 1:P117.9 P1 85.2

The higher crystallinity of Example 1 relative to Comparative Example 1is shown by the ATREF plot given in FIG. 5. As shown in FIG. 5, Example1 has higher temperature melting fractions than Comparative Example 1,the highly branched ethylene-based polymer. More importantly, the ATREFdistribution curve of Example 1 shows a relatively homogeneous curve,indicating a generally monomodal crystallinity distribution. Ifethylenic polymer Example 1 is merely a blend of separate components, itcould be expected to show a bimodal curve of two blended polymercomponents. Table 5 also shows that Example 1 has a portion of thepolymer which would elute at temperatures at or above 90° C. ComparativeExample 1 does not have a portion that elutes at or above 90° C.

The plot of FIG. 6 shows the ATREF plots of Example 2, Polymer 1, andComparative Example 1. In comparing the three plots, it is apparent thatExample 2 is different than both the highly long chain branchedethylene-based polymer (CE1) and the ethylene-based polymer (P1), andnot a mere blend. Comparative Example 1 has no elution above 90° C. P1has a significant amount of material eluting in the 90° C. or abovetemperature fraction (85.2%), indicating a predominance of the highcrystallinity ethylene-based polymer fraction. Example 2, similar toExample 1, shows a relatively homogeneous curve, indicating a relativelynarrow crystallinity distribution.

Additionally, a physical blend of an 80:20 weight ratio CE1:P1composition is compared against ethylenic polymer Example 2 in FIG. 6.The 80:20 weight ratio physical blend is created to compare to theestimated 27 weight percent ethylene-based polymer P1 and balance highlylong chain branched ethylene-based polymer composition that comprisesExample 2, as stated previously in the Preparation of Example EthylenicPolymers 1 and 2 section. The ATREF distribution in FIG. 6 shows the80:20 weight ratio blend has a well resolved bimodal distribution sinceit is made as a blend of two distinct polymers. As previously observed,ethylenic polymer Example 2 does not have a bimodal distribution.Additionally, as shown in Table 5, ethylenic polymer Example 2 has asmall amount of material eluting in the 90° C. or above temperaturefraction (5.3%), whereas the 80:20 weight ratio physical blend has anamount of elution (17.9%) reflective of its high crystallinityethylene-based polymer fraction.

Triple detector GPC (3D-GPC) using the Gel Permeation Chromatography(GPC) method, provided infra in the Testing Methods section, results aresummarized in Table 6.

TABLE 6 Triple detector GPC results, g′, and gpcBR analysis results forExamples 1 and 2, Comparative Example 1, and a 1 MI metallocenepolyethylene standard. Conventional GPC Absolute GPC Mn Mw Mz Mw Mz(abs)Mw (Abs) gpcBR Identification (g/mol) (g/mol) (g/mol) Mw/Mn (g/mol)(g/mol) Mz/Mw Mw(GPC) Whole g′ avg MH LCBf Example 1 11,950 51,570185,200 4.32 65,180 383,800 5.89 1.26 0.53 0.765 0.534 0.853 Comparative15,480 77,920 290,400 5.03 117,660 854,600 7.26 1.51 0.89 0.716 0.4640.973 Example 1 Example 2 16,140 74,760 198,100 4.63 96,660 327,400 3.391.29 0.64 0.725 0.532 0.780 Standard PE 41,350 115,630 241,100 2.80114,430 268,500 2.35 0.99 0.01 1.000 0.701 0.000 (1 MI Metallocene)

From Table 6 it can be seen that both Examples 1 and 2 show a narrowermolecular weight distribution, M_(w)/M_(n) ratio, by conventional GPCthan that of the highly long chain branched ethylene-based polymerComparative Example 1 (5.03 for the control; 4.32 for Example 1; and4.63 for Example 2). The narrower M_(w)/M_(n) ratio of both Examples canprovide benefits in physical properties, improved clarity, and reducedhaze over the Comparative Example 1 for film applications. TheM_(z)/M_(w) ratio from absolute GPC also distinguishes the ethylenicpolymer Examples with narrower values (5.89 and 3.39) and ComparativeExample 1 (7.26). The lower M_(z)/M_(w) ratio is associated withimproved clarity when used in films. The M_(w)(abs)/M_(w)(GPC) ratioshows that the Examples have lower values (1.26, 1.29) than theComparative Example 1 (1.51).

In Table 6, branching analysis using both g′ and gpcBR are alsoincluded. The g′ value is determined by using the g′ by 3D-GPC method,provided infra in the Testing Methods section. The gpcBR value isdetermined by using the gpcBR Branching Index by 3D-GPC method, providedinfra in the Testing Methods section. The lower gpcBR values for the twoethylenic Examples as compared to Comparative Example 1 and Example 2indicate comparatively less long chain branching; however, compared to a1 MI metallocene polymer, there is significant long chain branching inall the compositions.

Preparation of Example Ethylenic Polymers 3-5 Examples 3-5

This procedure is repeated for each Example. For each example, 2 gramsof resin of one of the ethylene-based polymers created in thePreparation of Ethylene-Based Polymers (that is, P1-3) are added to a100 ml autoclave reactor. Example 3 is comprised of P2. Example 4 iscomprised of P1. Example 5 is comprised of P3. The base properties ofthese polymers may be seen in Table 3. After closing the reactor, theagitator is turned on at 1000 rpm. The reactor is deoxygenated bypulling vacuum on the system, heating the reactor to 70° C. for onehour, and then flushing the system with nitrogen. After this, thereactor is pressurized with nitrogen and vacuum is pulled on thereactor. This step is repeated three times. The reactor is pressurizedwith ethylene up to 2000 bar while at ambient temperatures and ventedoff. This step is repeated three times. On the final ethylene vent, thepressure is dropped only to a pressure of about 100 bar and reactorheating is initiated. When the internal temperature reaches about 220°C., the reactor is then pressurized with ethylene to about 1600 bar andheld at 220° C. for at least 30 minutes. The estimated amount ofethylene in the reactor is 46.53 grams. Ethylene is then used to sweep3.9 ml of a mixture of 0.4321 mmol/ml propionaldehyde and 0.0008645mmol/ml tert-butyl peroxyacetate initiator in n-heptane into thereactor. Upon sweeping the initiator into the reactor, the pressure isincreased within the reactor to about 2000 bar, where free-radicalpolymerization is initiated. A temperature rise of the reactor to 240°C. is noted. After mixing for 15 minutes, the valve at the bottom of thereactor is opened and the pressure is lowered to between 50-100 bar tobegin recovering the resultant polymer. Then the reactor isrepressurized to 1600 bar, stirred for 3 minutes, and then the valve atthe bottom is opened to again lower the pressure to between 50-100 bar.For each Example, a total of about 6 grams of product polymer isrecovered from the reactor. Based upon the conversion value of ethylenein the reactor, each Example is comprised of about 33% weight percentethylene-based polymer and about 67% weight percent highly long chainbranched ethylene-based polymer formed during the free radicalpolymerization.

Comparative Example 2

Free-radical polymerization of ethylene under the same processconditions as given in Examples 3-5 without the addition of anyethylene-based polymer yields 4.64 grams of a highly long chain branchedethylene-based polymer designated as Comparative Example (CE) 2. Becauseno comonomer is used, Comparative Example 2 is an ethylene homopolymer.A temperature increase during the free radical reaction to 275° C. isnoted.

Characterization of Example Ethylenic Polymers 3-5

Ethylenic polymer Examples 3-5 are tested using both the DSCCrystallinity and Fast Temperature Rising Elution Fractionation methods,provided infra in the Testing Methods section. The results of thetesting of Examples 3-5 are compared to similar test results ofComparative Example 2, Polymers 1-3, and physical blends of ComparativeExample 2 with Polymers 1-3. The results are shown in Table 7.

TABLE 7 DSC analysis of Example 3-5, Polymers 1-3, Comparative Example2, and individual physical blends of P1-3 and CE2. Low High MeltingMelting Heat of Calculated Point Peak Point Peak Fusion Density DensitySample T_(m) (° C.) T_(m) (° C.) (J/g) (g/cm³) (g/cm³) Comparative NM110.7 148.7 0.921*  NM Example 2 P2 NM 130.0 239.5 NM 0.967 Example 3113.6 124.7 166.2 0.936** NM Blend 67:33 109.5 127.0 178.1 NM NM CE2:P2P1 NM 132.4 230.3 NM 0.965 Example 4 110.2 124.9 163.7 0.935** NM Blend67:33 109.5 128.9 173.9 NM NM CE2:P1 P3 NM 134.1 209.9 NM 0.958 Example5 111.4 123.8 158.5 0.933** NM Blend 67:33 109.0 129.4 170.9 NM NMCE2:P3 Note that “NM” designates not measured. Density values are takenfrom Table 3 for P1, P2, P3. Calculated Density for comparative example2 is determined using Equation 1. *Calculated using equation 1.**Calculated using (1/ρ) = ((w₁/ρ₁ + (w₂/ρ₂)) where ρ = density of theexample (g/cm³) and w₁ = weight fraction of CE2 described in Preparationof Example Ethylenic Polymers 3-5 for that example and ρ₁ = calculateddensity for CE2 from equation 1 and w₂ = weight fraction described inPreparation of Example Ethylenic Polymers 3-5 of either P1 or P2 or P3used for that example and ρ₂ = measured density for either P1 or P2 orP3 used for that example.

Using data from Tables 3, 4, and 7, a comparison plot between peakmelting temperature (T_(m)) and heat of fusion (H_(f)) comparingExamples 1-5, Comparative Examples 1 and 2, and Commercial AvailableResins 1-30 can be made to find relative relationships, such as therelationship shown in FIG. 7. Note in the case of materials withmultiple melting temperatures, the peak melting temperature is definedas the highest melting temperature. FIG. 7 reveals that all five of theExamples demonstrate different functional properties from the groupcreated by the Comparative Examples and the Commercially AvailableResins.

Due to the separation between the five ethylenic polymer Examples andthe group formed from the two Comparative Examples and the CommerciallyAvailable Resins, a line of demarcation between the groups to emphasizethe difference may be established for a given range of heats of fusion.As shown in FIG. 7, a numerical relationship, Equations 15, may be usedto represent such a line of demarcation:

T _(m)(° C.)=(0.2143*H _(f)(J/g))+79.643  (Eq. 15).

For such a relationship line, and as can be seen in FIG. 7, all fiveethylenic polymer Examples have at least a high melting point peak T_(m)equal to, if not greater than, a determined peak melting temperatureusing Equation 15 for a given heat of fusion value. In contrast, all ofthe Comparative Examples and Commercially Available Resins are below therelationship line, indicating their peak melting temperatures are lessthan a determined peak melting temperatures using Equation 15 for agiven heat of fusion value.

Also shown in FIG. 7, numerical relationships, Equations 16 and 17, mayalso be used to represent such a line of demarcation based upon therelationships between the Examples, Comparative Examples, andCommercially Available Resins as just discussed:

T _(m)(° C.)=(0.2143*H _(f)(J/g))+81  (Eq. 16),

More preferably T _(m)(° C.)=(0.2143*H _(f)(J/g))+85  (Eq. 17).

Tables 4 and 7 reveal a heat of fusion range for the Example ethylenicpolymers. The heat of fusion of the ethylenic polymers are from about120 to about 292 J/g, preferably from about 130 to about 170 J/g.

Tables 4 and 7 also show a peak melting temperature range for theExample ethylenic polymers. The peak melting temperature of theethylenic polymers are equal to or greater than about 100° C., andpreferably from about 100 to about 130° C.

Ethylenic polymer Examples 3-5, Comparative Example 2, and Polymers 1-3are tested using the Nuclear Magnetic Resonance method, provided infrain the Testing Methods section, to show comparative instances of shortchain branching. The results are shown in Table 8.

TABLE 8 Nuclear Magnetic Resonance analysis for short chain branchingdistribution in samples of Comparative Example 2 and ethylenic polymersExamples 3-5. Sample C1 C2 C3 C4 C5 C6+ Comparative Ex. 2 0.85 1.04 0.187.30 2.17 0.72 Ex. 3 ND 0.42 ND 3.70 1.68 0.40 Ex. 4 ND 0.35 ND 4.411.68 0.30 Ex. 5 ND 0.50 ND 4.61 1.46 0.62

For Table 8, “Cx” indicates the branch length in branches/1000 totalcarbons (C1=methyl, C5=amyl branch, etc.). “ND” stands for a result ofnone detected or observed at the given limit of detection.

Ethylene-based polymers P1-3, although tested, are not included in theresults of Table 8 because P1-3 did not exhibit C1-C6+ branching. Thisis expected as P1-3 are high crystallinity ethylene-based polymers thatdo not have any comonomer content that would produce short-chainbranches in the range tested.

As observed in Table 8, the ethylenic polymer Examples 3-5 show noappreciable C1 (methyl) or C3 (propyl) branching and C2, C4, and C5branching compared to Comparative Example 2. “Appreciable” means thatthe particular branch type is not observed above the limits of detectionusing the Nuclear Magnetic Resonance method (about 0.1 branches/1000carbons), provided infra in the Testing Methods section. ComparativeExample 2, a product of free-radical branching, shows significantbranching at all ranges. In some embodiment ethylenic polymers, theethylenic polymer has no “appreciable” propyl branches. In someembodiment ethylenic polymers, the ethylenic polymer has no appreciablemethyl branches. In some embodiment ethylenic polymers, at least 0.1units of amyl groups per 1000 carbon atoms are present. In someembodiment ethylenic polymers, no greater than 2.0 units of amyl groupsper 1000 carbon atoms are present.

Samples of Examples 3-5 are separated into subfractions using thePreparative Temperature Rising Elution Fractionation method, providedinfra in the Testing Methods section. The subfractions are combined intofour fractions, Fractions A-D, before the solvent is removed and thepolymers are recovered. FIG. 8 represents the temperature splits forFractions A-D using the method on Examples 3-5.

The Fractions are analyzed for weight and their weight averagetemperature determined. Table 9 summarizes the weight fractiondistribution of Examples 3-5 as well as Comparative Example 2 and giveseach Fraction its designation A-D.

TABLE 9 Weight fraction percent and fraction weight average temperaturefor fractions of Examples 3-5. Weight Fraction Fraction Weight AverageSample ID Fraction (wt %) Temperature (° C.) Example 3 A 11.27 98.5 B11.32 93.1 C 50.03 84.0 D 27.38 73.1 Example 4 A 15.76 98.4 B 12.53 93.1C 46.80 83.9 D 24.91 73.4 Example 5 A 17.90 98.4 B 17.79 93.4 C 35.8184.2 D 28.50 71.5

As can be seen in Table 9, Examples 3-5 have a significant amount ofpolymer eluting at a weight average temperature greater than 90° C. Forall three ethylenic polymer Examples there is at least one preparativeTREF fraction that elutes at 90° C. or greater (Fraction A and FractionB). For all three ethylenic polymer Examples at least 7.5% of theethylenic polymer elutes at a temperature of 90° C. or greater basedupon the total weight of the ethylenic polymer (Example 3: 22.59 wt %;Example 4: 28.29 wt %; Example 5: 25.69 wt %). For all three ethylenicpolymer Examples at least one preparative TREF fraction elutes at 95° C.or greater (Fraction A). For all three ethylenic polymer Examples atleast 5.0% of the ethylenic polymer elutes at a temperature of 95° C. orgreater based upon the total weight of the ethylenic polymer (Example 3:11.27 wt %; Example 4: 15.76 wt %; Example 5: 17.90 wt %).

Some of the Fractions are analyzed by triple detector GPC, and g′ andgpcBR values are determined using the g′ by 3D-GPC and gpcBR BranchingIndex by 3D-GPC methods, provided infra in the Testing Methods section.Comparative Example 2, Polymers 1-3, and representative weight ratiophysical blends based upon the estimated composition of Examples 3-5 ofrespective Polymers and Comparative Example 2 are analyzed. The resultsare shown in Table 10.

TABLE 10 Analysis using 3D-GPC for molecular weights, distributions, andmoments, g′, and gpcBR for select Fractions of Examples 3-5, Polymers1-3, and blends of P1-3 and CE2. Conventional GPC Absolute GPC Mn Mw MzMw Mz(abs) Mw (Abs) (g/mol) (g/mol) (g/mol) Mw/Mn (g/mol) (g/mol) Mz/MwMw(GPC) gpcBR g′ avg MH LCBf Comparative Example 2 10,840 46,840 151,6004.32 65,170 615,000 9.44 1.39 0.49 0.768 0.574 3.88 P2 5,950 17,10032,600 2.87 16,450 34,700 2.11 0.96 0.02 1.000 0.670 0 Example 3 12,59057,930 155,200 4.60 84,060 627,700 7.47 1.45 0.34 0.820 0.600 2.771Example 3 P-Tref Fraction 12,330 32,760 235,800 2.66 38,400 205,500 5.351.17 0.17 0.907 0.440 0.93 98.5° C. Fraction Example 3 P-Tref Fraction7,480 26,210 103,700 3.50 49,610 621,700 12.53 1.89 0.27 0.862 0.6362.767 93.1° C. Fraction Blend 67:33 CE 2/P 2 8,850 36,030 123,900 4.0747,390 494,800 10.44 1.32 0.379 0.844 0.551 0.963 P1 16,250 35,60061,500 2.19 36,110 66,500 1.84 1.01 0.01 1.000 0.702 0 Example 4 19,53080,880 197,200 4.14 100,170 496,500 4.96 1.24 0.30 0.829 0.625 1.704Example 4 P-Tref Fraction 15,780 50,050 120,600 3.17 74,240 247,100 3.331.48 0.31 0.842 0.621 0.779 93.1° C. Fraction Example 4 P-Tref Fraction14,020 58,390 126,800 4.16 93,850 1,370,100 14.6 1.61 0.30 0.806 0.6211.939 83.9° C. Fraction Blend 67:33 CE 2/P 1 11,930 43,730 141,800 3.6757,280 393,700 6.87 1.31 0.36 0.845 0.519 3.087 P3 31,390 72,970 131,3002.32 72,370 125,900 1.74 0.99 −0.01 1.000 0.671 0 Example 5 18,98090,500 210,400 4.77 122,830 616,700 5.02 1.36 0.39 0.789 0.627 2.206Example 5 P-Tref Fraction 18,640 74,780 141,100 4.01 116,940 2,172,20018.58 1.56 0.38 0.778 0.606 1.188 93.4° C. Fraction Blend 67:33 CE 2/P 312,130 54,140 135,900 4.46 69,260 329,500 4.76 1.28 0.263 0.855 0.6262.495

Table 10 show strong evidence of bonding between the ethylene-basedpolymers P1-3 and the highly long chain branched ethylene-based polymerformed in the reactor to form ethylenic polymers Examples 3-5. This canbe seen in the absolute GPC molecular weight. Comparing the molecularweight averages from both conventional and absolute GPCs of the Exampleswith their respective physical blends as listed in Table 10 show thedetected average molecular weights for the Examples are much higher thanthe blends, indicating chemical bonding.

The evidence of reaction is also strongly supported by the long chainbranching indices. All the gpcBR values for the Examples show thepresence of long chain branching in the high-temperature P-TREFFractions (Fractions A and B), which would usually be the temperaturerange reflective of high crystallinity and lack of LCBs. Forethylene-based polymers P1-3, the gpcBR value is at or near zero sincethey do not have any long chain branching. In addition, ethylene-basedpolymers such as P1-3 typically give a g′ index close to 1.0 and an MHexponent close to 0.72. As the level of long chain branching increases,the g′ index decreases from the value of 1.0; the MH exponent decreasesfrom 0.72; and the gpcBR index increases from the value of 0.Conventional highly long chain branched ethylene-based polymer, such asCE2, does not produce a fraction with both high crystallinity and highlevels of long chain branching.

In analyzing the samples for methyls per 1000 carbons, it is necessaryto combine Fractions into Fractions AB and CD to perform the Methyls per1000 Carbons Determination on P-TREF Fractions procedure, provided infrain the Testing Methods section due to the small sample size. Fractions Aand B are combined to give Fraction AB and Fractions C and D arecombined to give Fraction CD. The new weight average temperatures forFractions AB and CD are calculated in accordance with Equation 3.

FIG. 9 represents the temperature splits for combined Fractions AB andCD of Examples 3-5. FIG. 10 and Table 11 shows the two larger Fractionsand their weight fraction as a percentage of the whole polymer. Table 11and FIG. 11 show the methyls per 1000 carbon results.

TABLE 11 Weight Fraction and Fraction Weight Average Temperature forFractions of Examples 3-5. Fraction CD Fraction CD Fraction Fraction CDFraction AB Fraction AB Fraction AB Temperature Weight CD M_(n)Corrected Temperature Weight Fraction AB Corrected Sample ID (° C.)Fraction (GPC) Methyls/1000C (° C.) Fraction M_(n) (GPC) Methyls/1000CExample 3 80.15 0.77 18,288 12.4 95.80 0.23 17,562 1.6 Example 4 80.290.72 33,760 11.2 96.02 0.28 33,515 2.6 Example 5 78.57 0.64 24,470 10.595.90 0.36 58,201 4.6

Examples 3-5 show relatively high levels of branching in the hightemperature fraction, Fraction AB, as indicated by the methyls perthousand values. FIG. 11 is a plot of methyls per 1000 carbons(corrected for end groups or methyls) versus weight average elutiontemperature as determined by Methyls per 1000 Carbons Determination onP-TREF Fractions analysis of Fractions AB and CD for Examples 3-5 usingthe data from Table 11. The high temperature Fractions of the ethylenicpolymer Examples have higher than expected methyls per thousandcarbons—higher numbers than would be expected from merely a linearethylene-based polymer.

The results of Fast Temperature Rising Elution Fractionation testingshown in Table 12 also indicate strong evidence of long chain branchingand grafting in Examples 3-5. This can be seen in the LS-90 measuredM_(w) shown. Comparing the M_(w) of the Examples with their respectiveblends, the M_(w) of the respective Examples are all much higher thanthe respective blends.

TABLE 12 F-TREF results for Examples 3-5, Comparative Example 2, P1-3,and several representative physical blends. f-TREF Low-Melting Peakf-TREF High-Melting Peak Peak Temp. LS-90 Peak Temp. LS-90 Sample (° C.)Mw (° C.) Mw Comparative 76.39 64,073 ND ND Example 2 P2 ND ND 93.1817,191 Example 3 78.85 75,779 91.38 73,073 Blend 67:33 75.29 47,53292.52 46,766 CE 2/P2 P1 ND ND 94.87 33,888 Example 4 80.61 90,571 92.8887,853 Blend 67:33 75.40 50,157 93.85 50,128 CE 2/P1 P3 ND ND 95.3769,209 Example 5 79.59 101,326  91.46 107,875  Blend 67:33 75.27 46,45994.49 56,928 CE 2/P3 Note that “ND” means not determined.

FIGS. 13( a) and 13(b) show a 3D and 2D IR response curve, respectively,cross fractionation result for a Polymer 3 and Comparative Example 233:67 weight ratio physical blend based upon the Cross-Fractionation byTREF method, provided infra in the Testing Methods section. FIGS. 13( c)and 13(d) show the IR response curve using the same method for Example 5(which incorporates Polymer 3). FIGS. 13( a), (c), and (d) have a z-axis(Weight Fraction) in increments of 0.02, represented not only by gridlines (3D view only) but also by color bands (both 3D and 2D view). Thez-axis increments for Weight Fraction in FIG. 13( b) are set at 0.05 toassist in viewing the 2D representation.

Comparing the two sets of graphs, it can clearly be seen that the blendcomponents of FIGS. 13( a) and 13(b) are well resolved into two distinct“islands” of temperature elution versus molecular weight, indicating thebimodal nature of the blend. FIGS. 13( c) and 13(d) show Example 5 andhow the ethylenic polymer does not completely resolve, indicating asingle polymeric material. Also noteworthy is that the molecular weightsof the components of the blend are significantly lower than thecorresponding constituents of Example 5, which can be observed bycomparing FIG. 13( b) with FIG. 13( d).

‘While the embodiments have been described with particularity, it willbe understood that various other modifications will be apparent to andcan be readily made by those skilled in the art without departing fromthe spirit and scope of the invention. Accordingly, it is not intendedthat the scope of the claims to be limited to the examples anddescriptions set forth but rather that the claims be construed asencompassing all the features of patentable novelty which reside in thepresent invention, including all features which would be treated asequivalents by those skilled in the art to which the invention pertains.

It is intended that the disclosure of preferred or desired, morepreferred or more desired, highly preferred or highly desired, or mostpreferred or most desired substituents, ranges, end uses, processes, orcombinations with respect to any one of the disclosed compositions andmethods is applicable as well to any other of the preceding orsucceeding embodiments of the disclosed compositions and methods,independently of the identity of any other specific substituent, range,use, process, or combination.

Unless otherwise stated, implicit from the context or conventional inthe art, all parts and percentages are based on weight.

All applications, publications, patents, test procedures, and otherdocuments cited, including priority documents, are fully incorporated byreference to the extent such disclosure is not inconsistent with thedisclosed compositions and methods and for all jurisdictions in whichsuch incorporation is permitted.

Depending upon the context in which such values are described, andunless specifically stated otherwise, such values may vary by 1 percent,2 percent, 5 percent, or, sometimes, 10 to 20 percent. Whenever anumerical range with a lower limit, RL, and an upper limit, RU, isdisclosed, any number falling within the range, including the limitsthemselves is specifically disclosed. In particular, the followingnumbers within the range are specifically disclosed: R═RL+k*(RU−RL),wherein k is a variable ranging from 0.01 to 1.00 with a 0.01 increment,that is, k is 0.01 or 0.02 to 0.99 or 1.00. Moreover, any numericalrange defined by two R numbers as defined is also specificallydisclosed.

1-20. (canceled)
 21. An ethylenic polymer comprising at least onepreparative TREF fraction that elutes at 95° C. or greater using aPreparative Temperature Rising Elution Fractionation method, where atleast one preparative TREF fraction that elutes at 95° C. or greater hasa branching level greater than about 2 methyls per 1000 carbon atoms asdetermined by Methyls per 1000 Carbons Determination on P-TREFFractions, and where at least 5 weight percent of the ethylenic polymerelutes at a temperature of 95° C. or greater based upon the total weightof the ethylenic polymer.
 22. An ethylenic polymer comprising at leastone preparative TREF fraction that elutes at 95° C. or greater using aPreparative Temperature Rising Elution Fractionation method, where atleast one preparative TREF fraction that elutes at 95° C. or greater hasa g′ value of less than 1 as determined by g′ by 3D-GPC, and where atleast 5 weight percent of the ethylenic polymer elutes at a temperatureof 95° C. or greater based upon the total weight of the ethylenicpolymer.
 23. The ethylenic polymer of claim 22, where the g′ value isless than 0.95.
 24. A process, comprising: A) polymerizing ethylene inthe presence of a catalyst to form a linear ethylene-based polymerhaving a crystallinity of at least 50% as determined by DSCCrystallinity in a first reactor or a first part of a multi-partreactor; and B) reacting the linear ethylene-based polymer withadditional ethylene in the presence of a free-radical initiator to forman ethylenic polymer in at least one other reactor or a later part of amulti-part reactor.
 25. The process of claim 24, where the reaction ofstep (B) occurs by graft polymerization.
 26. The process of claim 24,where the catalyst of step (A) is a metallocene catalyst.
 27. Theprocess of claim 26, where polar compounds, if present in the firstreactor or the first part of a multi-part reactor, do not inhibit theactivity of the metallocene catalyst.